lp1-dif.htm - Generated by SEC Publisher for SEC Filing

497 1 lp1-dif.htm SUPPLEMENT TO PROSPECTUSES AND FINALIZED PROSPECTUSE lp1-dif.htm - Generated by SEC Publisher for SEC Filing

April 15, 2009

DREYFUS INVESTMENT FUNDS
- DREYFUS/THE BOSTON COMPANY SMALL CAP GROWTH FUND

Supplement to Prospectus
dated February 1, 2009
As revised, April 15, 2009

Effective as of the close of business on July 6, 2007, Dreyfus/The Boston Company Small Cap Growth Fund (the “Fund”) was closed to investments for new accounts, with certain exceptions. The Fund’s closure policy was subsequently modified on June 25, 2008, and, effective July 1, 2009, the Fund’s closure policy will be further modified.

Effective July 1, 2009, the following information supersedes and replaces any contrary information contained in the Fund’s Prospectus:

The Fund closed to new investors as of the close of business on July 6, 2007 (the “Closing Date”). Investors who did not own shares of the Fund at the Closing Date generally are not permitted to buy shares of the Fund, except that new accounts may be established by:

Participants in group employer retirement plans (and their successor plans), provided that the plan sponsor is approved by Dreyfus and has established the Fund as an investment option in the plan by the close of business on the Closing Date;
Wrap programs that have established the Fund as an investment option under the wrap program by the close of business on the Closing Date; and
The Fund’s primary portfolio managers and Fund Board members who do not have existing accounts.

Shareholders of the Fund as of the Closing Date may continue to make additional purchases and to reinvest dividends and capital gains into their existing Fund accounts.

Fund shareholders whose accounts have a zero balance on or after the Closing Date will be prohibited from reactivating the account or opening a new account, except that investors with zero balance accounts held under wrap fee programs or group employer retirement plans that were established by the close of business on the Closing Date may continue to make investments in such accounts. Financial institutions maintaining omnibus accounts with the Fund will be prohibited from accepting purchase orders from new investors after the Closing Date. After the Closing Date, investors may be required to demonstrate eligibility to buy shares of the Fund before an investment is accepted.

The Board reserves the right to open the Fund to new investors or suspend the sale of shares from time to time without further notice or supplement to the prospectus. The Fund may from time to time enter into capacity agreements with certain investors or financial intermediaries whereby the Fund agrees to reserve a specified maximum dollar amount of its remaining investment capacity to such investor or customers of such financial intermediary.

6941S0409

Dreyfus/The Boston Company

Small Cap Growth Fund

Seeks long-term growth of capital

by investing in equity securities of

small-cap U.S. companies

PROSPECTUS February 1, 2009

<R>As revised, April 15, 2009</R>


Contents


The Fund
Goal/Approach	1
Main Risks	2
Past Performance	4
Expenses	5
Management	6
Financial Highlights	8

Your Investment
Account Policies	9
Distributions and Taxes	14
Exchange Privilege	15
Account Instructions	16

For More Information
See back cover.

Note to Investors

The fund closed to new investors as of the close of business on July 6, 2007 (Closing Date). Shareholders of the fund as of the Closing Date may continue to buy shares in existing accounts. Shareholders whose accounts had a zero balance on or after the Closing Date are prohibited from reactivating the account or opening a new account. Investors who did not own shares of the fund at the Closing Date generally are not allowed to buy shares of the fund, except that new accounts may be established by: 1)(a) participants in qualified retirement plans (including pension or profit sharing plans, pension funds, 401(k) plans and other benefit plans), if the plan sponsor included the fund as an investment option on, and the plan owned shares of the fund as of, the Closing Date, or (b) the plan has been approved by an officer of Dreyfus Investment Funds and provided Dreyfus is able to effectively manage the additional assets in accordance with the fund’s investment strategy; 2) certain institutional investors and financial professionals (including investment advisers, broker-dealers, banks and trust companies), either for themselves or on behalf of clients, if approved by an officer of Dreyfus Investment Funds and provided that Dreyfus is able to effectively manage the additional assets in accordance with the fund’s investment strategy; and 3) certain existing and prospective advisory clients of TBCAM or Dreyfus, and of their affiliates, upon the request of TBCAM or Dreyfus, provided that Dreyfus is able to effectively manage the additional assets in accordance with the fund’s investment strategy. Investors may be required to demonstrate eligibility to buy shares of the fund before an investment is accepted.

The Board reserves the right to open the fund to new investors or suspend the sale of shares from time to time without further notice or supplement to the prospectus. The fund may from time to time enter into capacity agreements with certain investors or financial intermediaries whereby the fund agrees to reserve a specified maximum dollar amount of its remaining investment capacity to such investor or customers of such financial intermediary.

The Fund

Dreyfus/The Boston Company Small Cap Growth Fund

Ticker Symbol SSETX

GOAL/APPROACH

Although the fund normally invests in U.S.-based companies, it may invest up to 15% of its assets in foreign companies, including up to 10% of its assets in issuers located in emerging market countries, and up to 3% of its assets in issuers of any one specific emerging market country.The fund also may invest up to 20% of its assets in high grade fixed-income securities (i.e., rated A or better or the unrated equivalent) with remaining maturities of three years or less, and may invest up to 5% of its assets in fixed-income securities in the lowest long-term investment grade category (i.e., rated Baa-/BBB- or the unrated equivalent).

The portfolio managers employ a growth-oriented investment style in managing the fund’s portfolio, which means the portfolio managers seek to identify those small-cap companies which are experiencing or are expected to experience rapid earnings or revenue growth. The portfolio managers focus on high quality companies, especially those with products or services that are believed to be leaders in their market niches. The portfolio managers focus on individual stock selection instead of trying to predict which industries or sectors will perform best and select stocks by:

Using fundamental research to identify and follow companies considered to have attractive characteristics, such as strong business and competitive positions, solid cash flows and balance sheets, high quality management and high sustainable growth; and
Investing in a company when the portfolio managers’ research indicates that the company will experience accelerating revenues and expanding operating margins, which may lead to rising estimate trends and favorable earnings surprises.

The fund’s investment strategy may lead it to emphasize certain sectors, such as technology, health care, business services and communications.

The fund may, but is not required to, use derivatives, such as futures, options and forward contracts, as a substitute for investing directly in an underlying asset, to increase returns or as part of a hedging strategy. Generally, the fund would enter into equity index futures contracts based primarily on the Russell 2000 Index.

Concepts to understand

Small-cap companies: generally new and often entrepreneurial companies. Small-cap companies tend to grow faster than large-cap companies, but frequently are more volatile, more vulnerable to major setbacks and have a higher failure rate than larger companies.

Growth companies: companies whose earnings are expected to grow faster than the overall market. Often, growth stocks pay little or no dividends, have relatively high price-to-earnings and price-to-book ratios, and tend to be more volatile than value stocks.

Russell 2000 Growth Index: an unmanaged index, which is the fund’s benchmark index, that measures the performance of those Russell 2000 companies (the 2000 smallest companies in the Russell 3000^®Index, which represents approximately 10% of the total market capitalization of the Russell 3000 Index) with higher price-to-book ratios and higher forecasted growth values.

The Fund 1

MAIN RISKS

The fund’s principal risks are discussed below. An investment in the fund is not a bank deposit. It is not insured or guaranteed by the FDIC or any other government agency. It is not a complete investment program. The value of your investment in the fund will fluctuate, sometimes dramatically, which means you could lose money.

Market risk. The market value of a security may decline due to general market conditions that are not specifically related to a particular company, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates or adverse investor sentiment generally. A security’s market value also may decline because of factors that affect a particular industry or industries, such as labor shortages or increased production costs and competitive conditions within an industry.
Issuer risk. The value of a security may decline for a number of reasons which directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer’s products or services.
Small company risk. Small companies carry additional risks because their operating histories tend to be more limited, their earnings and revenues less predictable (and some companies may be experiencing significant losses), and their share prices more volatile than those of larger, more established companies.The shares of smaller companies tend to trade less frequently than those of larger, more established companies, which can adversely affect the pricing of smaller companies’ securities and the fund’s ability to sell them when the portfolio managers deem it appropriate.These companies may have limited product lines, markets and/or financial resources, or may depend on a limited management group. Some of the fund’s investments will rise and fall based on investor perception rather than economic factors. Other investments, including special situations, are made in anticipation of future products and services or events whose delay or cancellation could cause the stock price to drop.
Growth stock risk. Investors often expect growth companies to increase their earnings at a certain rate. If these expectations are not met, investors can punish the stocks inordinately, even if earnings do increase. In addition, growth stocks typically lack the dividend yield that may cushion stock prices in market downturns
Market sector risk.The fund may significantly overweight or underweight certain companies, industries or market sectors, which may cause the fund’s performance to be more or less sensitive to developments affecting those companies, industries or sectors.
Foreign investment risk. To the extent the fund invests in foreign securities, its performance will be influenced by political, social and economic factors affecting investments in foreign companies. Special risks associated with investments in foreign companies include exposure to currency fluctuations, less liquidity, less developed or less efficient trading markets, lack of comprehensive company information, political and economic instability and differing auditing and legal standards.
Foreign currency risk. Investments in foreign currencies are subject to the risk that those currencies will decline in value relative to the U.S. dollar, or, in the case of hedged positions, that the U.S. dollar will decline relative to the currency being hedged. Currency rates in foreign countries may fluctuate significantly over short periods of time.A decline in the value of foreign currencies relative to the U.S. dollar will reduce the value of securities held by the fund and denominated in those currencies. Foreign currencies are also subject to risks caused by inflation, interest rates, budget deficits and low savings rates, political factors and government controls.
Emerging market risk. Emerging markets tend to be more volatile than the markets of more mature economies, and generally have less diverse and less mature economic structures and less stable political systems than those of developed countries. The securities of companies located in emerging markets are often subject to rapid and large changes in price.

Derivatives risk. The fund may use derivative instruments, such as options, futures and options on futures (including those relating to securities, indexes, foreign currencies and interest rates), and forward contracts. A small investment in derivatives could have a potentially large impact on the fund’s performance. The use of derivatives involves risks different from, or possibly greater than, the risks associated with investing directly in the underlying assets. Derivatives can be highly volatile, illiquid and difficult to value, and there is the risk that changes in the value of a derivative held by the fund will not correlate with the underlying instruments or the fund’s other investments. Derivative instruments also involve the risk that a loss may be sustained as a result of the failure of the counterparty to the derivative instruments to make required payments or otherwise comply with the derivative instruments’ terms.
Leveraging risk. The use of leverage, such as engaging in reverse repurchase agreements, lending portfolio securities, entering into futures contracts or forward currency contracts and engaging in forward commitment transactions may magnify the fund’s gains or losses.
IPO risk. The fund may purchase securities of companies in IPOs.The prices of securities purchased in IPOs can be very volatile.The effect of IPOs on the fund’s performance depends on a variety of factors, including the number of IPOs the fund invests in relative to the size of the fund and whether and to what extent a security purchased in an IPO appreciates or depreciates in value. As a fund’s asset base increases, IPOs often have a diminished effect on such fund’s performance.

Other potential risks

Under adverse market conditions, the fund could invest some or all of its assets in U.S. Treasury securities and money market securities. Although the fund would do this for temporary defensive purposes, it could reduce the benefit from any upswing in the market. During such periods, the fund may not achieve its investment objective.

The fund may engage in short-term trading, which could produce higher transaction costs and taxable distributions and lower the fund’s after-tax performance.

An investment in fixed-income securities will be subject primarily to interest rate and credit risks. Prices of bonds tend to move inversely with changes in interest rates. Typically, a rise in rates will adversely affect bond prices and, to the extent the fund invests in bonds, the fund’s share price. The longer the effective maturity and duration of these investments, the more likely the fund’s share price will react to changes in interest rates. Credit risk is the risk that the issuer of the security will fail to make timely interest or principal payments, and includes the possibility that any of the fund’s fixed-income investments will have its credit rating downgraded.

The fund may lend its portfolio securities to brokers, dealers and other financial institutions. In connection with such loans, the fund will receive collateral from the borrower equal to at least 100% of the value of the loaned securities. If the borrower of the securities fails financially, there could be delays in recovering the loaned securities or exercising rights to the collateral.

The Fund 3

PAST PERFORMANCE

The bar chart and table shown illustrate the risks of investing in the fund. The bar chart shows the changes in the fund’s performance from year to year. The table compares the fund’s average annual total returns to those of the Russell 2000 Growth Index, a broad measure of small cap growth stock performance. All returns assume reinvestment of dividends and distributions. Of course, past performance (before and after taxes) is no guarantee of future results.

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After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements such as 401(k) or other retirement plans.

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Year-by-year total returns as of 12/31 each year (%)

Fund shares


Best Quarter:	Q4 ‘99	+68.45%
Worst Quarter:	Q4 ‘08	-26.46%

*The fund’s performance in 1999 should be considered extraordinary due to particularly favorable market conditions which are unlikely to reoccur.

Average annual total returns as of 12/31/08


	1 Year	5 Years	10 Years

Fund
returns before taxes	-37.46%	-0.29%	4.74%

Fund
returns after taxes
on distributions	-37.46%	-0.29%	4.18%

Fund
returns after taxes
on distributions and
sale of fund shares	-24.35%	-0.24%	3.91%

Russell 2000
Growth Index
reflects no deduction for
fees, expenses or taxes	-38.54%	-2.35%	-0.76%

EXPENSES

As an investor, you pay certain fees and expenses in connection with the fund, which are described in the table below.Annual fund operating expenses are paid out of fund assets, so their effect is included in the share price.The fund has no sales charge (load) or Rule 12b-1 distribution fees.

Fee table

Annual fund operating expenses
(expenses paid from fund assets)
% of average daily net assets


Management fees	.80
Other expenses	.21
Total	1.01


Expense example
1 Year	3 Years	5 Years	10 Years
$103	$322	$558	$1,236

This example shows what you could pay in expenses over time. It uses the same hypothetical conditions other funds use in their prospectuses: $10,000 initial investment, 5% total return each year and no changes in expenses. The figures shown would be the same whether you sold your shares at the end of the period or kept them. Because actual returns and expenses will be different, the example is for comparison only.

Concepts to understand

Management fee: the fee paid to Dreyfus for managing the fund’s portfolio and assisting in all aspects of the fund’s operations.

Other expenses: fees paid by the fund for miscellaneous items such as transfer agency, custody, administration, professional and registration fees, and include an administrative services fee of up to 0.15% payable to certain financial intermediaries, including affiliates, who provide sub-administration, recordkeeping and/or sub-transfer agency services to beneficial owners of the fund.

The Fund 5

MANAGEMENT

Investment adviser

The investment adviser for the fund is Dreyfus, 200 Park Avenue, NewYork, NewYork 10166. Founded in 1947, Dreyfus manages approximately $354 billion in approximately 200 mutual fund portfolios. Dreyfus is the primary mutual fund business of The Bank of New York Mellon Corporation (BNY Mellon), a global financial services company focused on helping clients move and manage their financial assets, operating in 34 countries and serving more than 100 markets. BNY Mellon is a leading provider of financial services for institutions, corporations and high-net-worth individuals, providing asset and wealth management, asset servicing, issuer services, and treasury services through a worldwide client-focused team. BNY Mellon has more than $23 trillion in assets under custody and administration and $1.1 trillion in assets under management, and it services more than $13 trillion in outstanding debt.Additional information is available at www.bnymellon.com.

The Dreyfus asset management philosophy is based on the belief that discipline and consistency are important to investment success. For each fund, Dreyfus seeks to establish clear guidelines for portfolio management and to be systematic in making decisions.This approach is designed to provide each fund with a distinct, stable identity.

Effective on December 1, 2008 (Effective Date), Dreyfus was appointed to serve as the fund’s investment adviser. Prior to the Effective Date, The Boston Company Asset Management, LLC (TBCAM), an affiliate of Dreyfus, was the investment adviser for the fund. For the past fiscal year, the fund paid TBCAM an investment advisory fee at the annual rate of 0.80% of the fund’s average daily net assets. A discussion regarding the basis for the board’s approving the fund’s investment advisory agreement with Dreyfus is available in the fund’s annual report dated September 30, 2008.

B. Randall Watts, Jr. and P. Hans Von Der Luft are the fund’s primary portfolio managers, positions they have held since September 2001 and September 2005, respectively. Mr. Watts is a senior vice president and is the lead portfolio manager for the U.S. small-cap and micro-cap growth investment team at TBCAM, where he has been employed since 2003. He is also responsible for conducting research covering the technology and industrial sectors. Mr. Von Der Luft is a portfolio manager for the U.S. small-cap value equity strategies and a member of the portfolio management team for the U.S. small-cap growth strategies at TBCAM, where he has been employed since July 2003. He is also responsible for conducting research covering the health care and finance sectors. Mr. Watts and Mr.Von Der Luft have been employed by Dreyfus since December 2008. As dual employees of Dreyfus andTBCAM, Mr.Watts and Mr.Von Der Luft manage the fund as employees of Dreyfus but use TBCAM’s proprietary investment process.

The fund’s Statement of Additional Information (SAI) provides additional information about the portfolio managers’ compensation, other accounts managed by the portfolio managers, and the portfolio managers’ ownership of fund shares.

Distributor

The fund’s distributor is MBSC Securities Corporation (MBSC), a wholly-owned subsidiary of Dreyfus. Dreyfus or MBSC may provide cash payments out of its own resources to financial intermediaries that sell shares of the fund or provide other services. Such payments are separate from any other expenses paid by the fund to those intermediaries. Because those payments are not made by you or the fund, the fund’s total expense ratio will not be affected by any such payments.These additional payments may be made to intermediaries, including affiliates, that provide shareholder servicing, sub-administration, recordkeeping and/or sub-transfer agency services, marketing support and/or access to sales meetings, sales representatives and management representatives of the financial intermediary. Cash compensation also may be paid from Dreyfus’ or MBSC’s own resources to intermediaries for inclusion of the fund on a sales list, including a preferred or select sales list or in other sales programs. These payments sometimes are referred to as “revenue sharing.” From time to time, Dreyfus or MBSC also may provide cash or non-cash compensation to financial intermediaries or their representatives in the form of occasional gifts; occasional meals, tickets or other entertainment; support for due diligence trips; educational conference sponsorship; support for recognition programs; and other forms of cash or non-cash compensation permissible under broker-dealer regulations. In some cases, these payments or compensation may create an incentive for a financial intermediary or its employees to recommend or sell shares of the fund to you. Please contact your financial representative for details about any payments they or their firm may receive in connection with the sale of fund shares or the provision of services to the fund.

Code of ethics

The fund, Dreyfus and MBSC have each adopted a code of ethics that permits its personnel, subject to such code, to invest in securities, including securities that may be purchased or held by the fund.The Dreyfus code of ethics restricts the personal securities transactions of its employees, and requires portfolio managers and other investment personnel to comply with the code’s preclearance and disclosure procedures.The primary purpose of the code is to ensure that personal trading by Dreyfus employees does not disadvantage any Dreyfus-managed fund.

The Fund 7

FINANCIAL HIGHLIGHTS

This table describes the fund’s performance for the fiscal periods indicated. “Total return” shows how much your investment in the fund would have increased (or decreased) during each period, assuming you had reinvested all dividends and distributions. These financial highlights have been audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm, whose report on the fund’s financial statements containing the financial highlights, is included in the annual report, which is available upon request.


		Year Ended September 30,
	2008	2007	2006	2005	2004^(a)
Net Asset Value, Beginning of Year	$59.41	$49.67	$46.30	$37.95	$32.41
From Investment Operations:
Net investment income (loss)*^(b)	(0.11)	(0.11)	(0.14)	(0.20)	(0.33)
Net realized and unrealized gains (loss) on investments	(9.41)^(c)	9.85^(c)	3.51	8.55	5.87^(c)
Total from operations	(9.52)	9.74	3.37	8.35	5.54
Net Asset Value, End of Year	$49.89	$59.41	$49.67	$46.30	$37.95
Total Return	(16.02)%	19.61%	7.28%^(d)22.00%^(d)17.09%^(d)
Ratios/Supplemental Data:
Expenses (to average daily net assets)*	1.01%	1.09%^(e)	1.10%^(e)	1.17%^(e)	1.18%^(e)
Net Investment Income (Loss) (to average daily net assets)*	(0.20)%	(0.20)%	(0.30)%	(0.48)%	(0.87)%
Portfolio Turnover	207%	175%^(f)	166%^(f)	135%^(f)	153%^(f)
Net Assets, End of Year (000’s omitted)	$232,706	$186,991	$42,103	$36,323	$18,274

____________________

* For the periods indicated, TBCAM, the fund’s former investment adviser, voluntarily agreed not to impose a portion of its investment

advisory fee and/or reimbursed the fund for all or a portion of its operating expenses. If this voluntary action had not been taken, the

investment income per share and the ratios without waivers and reimbursements would have been:


Net investment income (loss) per share^(b)	n/a	n/a	$(0.28)	$(0.31)	$(0.40)
Ratios (to average daily net assets):
Expenses	n/a	n/a	1.38^(e)	1.41^(e)	1.37^(e)
Net investment income (loss)	n/a	n/a	(0.58)%	(0.72)%	(1.06)%


(a) Prior to August 31, 2005, the fund offered two classes of shares: Institutional Class and Service Class.The financial highlights for periods prior to the year ended
	September 30, 2005, represent those of the Institutional Class.
(b) Calculated based on average shares outstanding.
(c)	Amounts include litigation proceeds received by the fund of $0.01 for the year ended September 30, 2008, $0.01 for the year ended September 30, 2007 and
	$0.06 for the year ended September 30, 2004.
(d) Total return would have been lower in the absence of expense waivers.
(e)	For the period October 1, 2006 to September 19, 2007, and for the fiscal years ended September 30, 2004-2006, the ratios include the fund’s share of TBC
	Small Cap Growth Portfolio’s (the Portfolio) allocated expenses.
(f)	On September 19, 2007, the fund, which had owned 100% of the Portfolio on such date, withdrew entirely from the Portfolio and received the Portfolio’s securities
	and cash in exchange for its interests in the Portfolio. Effective September 20, 2007, the fund began investing directly in the securities in which the Portfolio had
	invested. Portfolio turnover represents investment activity of both the fund and the Portfolio for the year.The amounts shown for 2004-2006 are the ratios for the
	Portfolio.

Your Investment

ACCOUNT POLICIES

The fund is designed primarily for people who are investing through a third party, such as a bank, broker-dealer or financial adviser, or for a 401(k) or other retirement plan.Third parties with whom you open a fund account may impose policies, limitations and fees which are different from those described in this prospectus. Consult a representative of your plan or financial institution for further information.

Shares of the fund are available only to limited types of investors, and may be purchased by:

bank trust departments, trust companies and insurance companies that have entered into agreements with the fund’s distributor to offer fund shares to their clients
institutional investors acting in a fiduciary, advisory, agency, custodial or similar capacity for qualified or non-qualified employee benefit plans, including pension, profit-sharing and other deferred compensation plans, whether established by corporations, partnerships, non-profit entities, trade or labor unions, or state and local governments, and IRAs set up under Simplified Employee Pension Plans that have entered into agreements with the fund’s distributor to offer fund shares to such plans
law firms or attorneys acting as trustees or executors/administrators
foundations and endowments that make an initial investment in the fund of at least $1 million
sponsors of college savings plans that qualify for tax-exempt treatment under Section 529 of the Internal Revenue Code, that maintain an omnibus account with the fund and do not require shareholder tax reporting or 529 account support responsibilities from the fund’s distributor
advisory fee-based accounts offered through financial intermediaries who, depending on the structure of the selected advisory platform, make fund shares available

You pay no sales charges to invest in the fund. Your price for fund shares is the fund’s net asset value per share (NAV), which is generally calculated as of the close of trading on the NewYork Stock Exchange (usually 4:00 p.m. Eastern time) on days the exchange is open for regular business.

Your order will be priced at the next NAV calculated after your order is received in proper form by the fund’s transfer agent or other authorized entity.

When calculating its NAV, the fund’s investments are valued on the basis of market quotations or official closing prices. If market quotations or official closing prices are not readily available, or are determined not to reflect accurately fair value (such as when the value of a security has been materially affected by events occurring after the close of the exchange or market on which the security is principally traded (for example, a foreign exchange or market), but before the fund calculates its NAV), the fund may value those investments at fair value as determined in accordance with procedures approved by the fund’s board. Fair value of investments may be determined by the fund’s board, its pricing committee or its valuation committee in good faith using such information as it deems appropriate under the circumstances. Fair value of foreign equity securities may be determined with the assistance of a pricing service using correlations between the movement of prices of foreign securities and indexes of domestic securities and other appropriate indicators, such as closing market prices of relevant ADRs and futures contracts. Using fair value to price securities may result in a value that is different from a security’s most recent closing price and from the prices used by other mutual funds to calculate their net asset values. Forward currency contracts will be valued at the current cost of offsetting the contract. Foreign securities may trade on days when the fund does not calculate its NAV and thus may affect the fund’s NAV on days when investors have no access to the fund.

Your Investment 9

ACCOUNT POLICIES (continued)

Investments in small capitalization equity securities, foreign securities and certain other thinly traded securities may provide short-term traders arbitrage opportunities with respect to the fund’s shares. For example, arbitrage opportunities may exist when trading in a portfolio security or securities is halted and does not resume, or the market on which such securities are traded closes before the fund calculates its NAV. If short-term investors in the fund were able to take advantage of these arbitrage opportunities, they could dilute the NAV of fund shares held by long-term investors. Portfolio valuation policies can serve to reduce arbitrage opportunities available to short-term traders, but there is no assurance that such valuation policies will prevent dilution of the fund’s NAV by short-term traders. While the fund has a policy regarding frequent trading, it too may not be completely effective to prevent short-term NAV arbitrage trading, particularly in regard to omnibus accounts. Please see “Your Investment — Account Policies — General Policies” for further information about the fund’s frequent trading policy.

Concept to understand

Net asset value (NAV): a mutual fund’s share price on a given day. A fund’s NAV is calculated by dividing the value of its net assets by the number of its existing shares outstanding.


Minimum investments^†
	Initial	Additional
Regular accounts	$1,000	$100

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All investments must be in U.S. dollars. Third-party checks, cash, travelers’ checks or money orders will not be accepted. You may be charged a fee for any check that does not clear.

^†The minimum initial investment for foundations and endowments is

$1 million.

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Selling shares

You may sell (redeem) shares at any time. Your shares will be sold at the next NAV calculated after your order is received in proper form by the fund’s transfer agent or other authorized entity. Any certificates representing fund shares being sold must be returned with your redemption request.Your order will be processed promptly and you will generally receive the proceeds within a week.

Before selling shares recently purchased by check, please note that:

if you send a written request to sell such shares, the fund may delay sending the proceeds for up to eight business days following the purchase of those shares
the fund will not process wire or telephone redemption requests for up to eight business days following the purchase of those shares


Limitations on selling shares by phone

Proceeds	Minimum	Maximum
sent by	phone	phone

Check	no minimum	$250,000 per day

Wire	$1,000	$500,000 for joint
		accounts every 30 days/
		$20,000 per day

Written sell orders

Some circumstances require written sell orders along with signature guarantees. These include:

amounts of $10,000 or more on accounts whose address has been changed within the last 30 days
requests to send the proceeds to a different payee or address

Written sell orders of $100,000 or more must also be signature guaranteed.

A signature guarantee helps protect against fraud. You can obtain one from most banks or securities dealers, but not from a notary public. For joint accounts, each signature must be guaranteed. Please call to ensure that your signature guarantee will be processed correctly.

Your Investment 11

ACCOUNT POLICIES (continued)

General policies

Unless you decline teleservice privileges on your application, the fund’s transfer agent is authorized to act on telephone instructions from any person representing himself or herself to be you and reasonably believed by the transfer agent to be genuine. You may be responsible for any fraudulent telephone order as long as the fund’s transfer agent takes reasonable measures to confirm that instructions are genuine.

The fund is designed for long-term investors. Frequent purchases, redemptions and exchanges may disrupt portfolio management strategies and harm fund performance by diluting the value of fund shares and increasing brokerage and administrative costs. As a result, Dreyfus and the fund’s board have adopted a policy of discouraging excessive trading, short-term market timing, and other abusive trading practices (frequent trading) that could adversely affect the fund or its operations. Dreyfus and the fund will not enter into arrangements with any person or group to permit frequent trading.

The fund reserves the right to:

change or discontinue its exchange privilege, or temporarily suspend the privilege during unusual market conditions
change its minimum or maximum investment amounts
delay sending out redemption proceeds for up to seven days (generally applies only during unusual market conditions or in cases of very large redemptions or excessive trading)
“redeem in kind,” or make payments in securities rather than cash, if the amount redeemed is large enough to affect fund operations (for example, if it exceeds 1% of the fund’s assets)
refuse any purchase or exchange request, including those from any individual or group who, in Dreyfus’ view, is likely to engage in frequent trading

More than four roundtrips within a rolling 12-month period generally is considered to be frequent trading.A roundtrip consists of an investment that is substantially liquidated within 60 days. Based on the facts and circumstances of the trades, the fund may also view as frequent trading a pattern of investments that are partially liquidated within 60 days.

Transactions made through Automatic Investment Plans,Automatic Withdrawal Plans, automatic non-discretionary rebalancing programs, and minimum required retirement distributions generally are not considered to be frequent trading. For employer-sponsored benefit plans, generally only participant-initiated exchange transactions are subject to the roundtrip limit.

Dreyfus monitors selected transactions to identify frequent trading. When its surveillance systems identify multiple roundtrips, Dreyfus evaluates trading activity in the account for evidence of frequent trading. Dreyfus considers the investor’s trading history in other accounts under common ownership or control, in other Dreyfus Funds and BNY Mellon Funds, and if known, in non-affiliated mutual funds and accounts under common control. These evaluations involve judgments that are inherently subjective, and while Dreyfus seeks to apply the policy and procedures uniformly, it is possible that similar transactions may be treated differently. In all instances, Dreyfus seeks to make these judgments to the best of its abilities in a manner that it believes is consistent with shareholder interests. If Dreyfus concludes the account is likely to engage in frequent trading, Dreyfus may cancel or revoke the purchase or exchange on the following business day. Dreyfus may also temporarily or permanently bar such investor’s future purchases into the fund in lieu of, or in addition to, canceling or revoking the trade. At its discretion, Dreyfus may apply these restrictions across all accounts under common ownership, control or perceived affiliation.

Fund shares often are held through omnibus accounts maintained by financial intermediaries, such as brokers and retirement plan administrators, where the holdings of multiple shareholders, such as all the clients of a particular broker, are aggregated. Dreyfus’ ability to monitor the trading activity of investors whose shares are held in omnibus accounts is limited. However, the agreements between the distributor and financial intermediaries include obligations to comply with the terms of this prospectus and to provide Dreyfus, upon request, with information concerning the trading activity of investors whose shares are held in omnibus accounts. If Dreyfus determines that any such investor has engaged in frequent trading of fund shares, Dreyfus may require the intermediary to restrict or prohibit future purchases or exchanges of fund shares by that investor.

Certain retirement plans and intermediaries that maintain omnibus accounts with the fund may have developed policies designed to control frequent trading that may differ from the fund’s policy.At its sole discretion, the fund may permit such intermediaries to apply their own frequent trading policy. If you are investing in fund shares through an intermediary (or in the case of a retirement plan, your plan sponsor), please contact the intermediary for information on the frequent trading policies applicable to your account.

To the extent that the fund significantly invests in thinly traded small-capitalization equity securities, certain investors may seek to trade fund shares in an effort to benefit from their understanding of the value of these securities (referred to as price arbitrage). Any such frequent trading strategies may interfere with efficient management of the fund’s portfolio to a greater degree than funds that invest in highly liquid securities, in part because the fund may have difficulty selling these portfolio securities at advantageous times or prices to satisfy large and/or frequent redemption requests. Any successful price arbitrage may also cause dilution in the value of fund shares held by other shareholders.

To the extent that the fund significantly invests in foreign securities traded on markets that close before the fund calculates its NAV, events that influence the value of these foreign securities may occur after the close of these foreign markets and before the fund calculates its NAV. As a result, certain investors may seek to trade fund shares in an effort to benefit from their understanding of the value of these foreign securities at the time the fund calculates its NAV (referred to as price arbitrage). This type of frequent trading may dilute the value of fund shares held by other shareholders.The fund has adopted procedures designed to adjust closing market prices of foreign equity securities under certain circumstances to reflect what it believes to be their fair value.

Although the fund’s frequent trading and fair valuation policies and procedures are designed to discourage market timing and excessive trading, none of these tools alone, nor all of them together, completely eliminates the potential for frequent trading.

Third-party investments

If you invest through a third party (rather than directly with the distributor), the policies and fees may be different than those described herein. Banks, brokers, 401(k) plans, financial advisers and financial supermarkets may charge transaction fees and may set different minimum investments or limitations on buying or selling shares. Consult a representative of your plan or financial institution for further information.

Small account policy

If your account falls below $500, the fund may ask you to increase your balance. If it is still below $500 after 30 days, the fund may close your account and send you the proceeds.

Your Investment 13

DISTRIBUTIONS AND TAXES

The fund earns dividends, interest and other income from its investments, and distributes this income (less expenses) to shareholders as dividends. The fund also realizes capital gains from its investments, and distributes these gains (less any losses) to shareholders as capital gain distributions. The fund normally pays dividends semiannually and distributes any capital gains annually. Fund dividends and capital gain distributions will be reinvested in the fund unless you instruct the fund otherwise.There are no fees or sales charges on reinvestments.

Distributions paid by the fund are subject to federal income tax, and may also be subject to state or local taxes (unless you are investing through a tax-advantaged retirement account). For federal tax purposes, in general, certain fund distributions, including distributions of short-term capital gains, are taxable to you as ordinary income. Other fund distributions, including dividends from U.S. companies and certain foreign companies and distributions of long-term capital gains, generally are taxable to you as qualified dividends and capital gains, respectively.

High portfolio turnover and more volatile markets can result in significant taxable distributions to shareholders, regardless of whether their shares have increased in value.The tax status of any distribution generally is the same regardless of how long you have been in the fund and whether you reinvest your distributions or take them in cash.

If you buy shares of a fund when the fund has realized but not yet distributed income or capital gains, you will be “buying a dividend” by paying the full price for the shares and then receiving a portion back in the form of a taxable distribution.

Your sale of shares, including exchanges into other funds, may result in a capital gain or loss for tax purposes. A capital gain or loss on your investment in the fund generally is the difference between the cost of your shares and the amount you receive when you sell them.

The tax status of your distributions will be detailed in your annual tax statement from the fund. Because everyone’s tax situation is unique, please consult your tax advisor before investing.

EXCHANGE PRIVILEGE

You can exchange shares worth $500 or more (no minimum for retirement accounts) of the fund for Class I shares of other Dreyfus funds or for shares of certain other Dreyfus funds. You can request your exchange in writing or by phone. Be sure to read the current prospectus for any fund into which you are exchanging before investing. Any new account established through an exchange will have the same privileges as your original account (as long as they are available).There is currently no fee for exchanges, although you may be charged a sales load when exchanging into any fund that has one.

Your Investment 15

For information and other assistance, call toll free
in the U.S. 1-800-645-6561.

Outside the U.S. 516-794-5452

Make checks payable to: The Dreyfus Family of Funds.

Concept to understand

Wire transfer: for transferring money from one financial
institution to another. Wiring is the fastest way to move
money, although your bank may charge a fee to send or
receive wire transfers. Wire redemptions from the fund are
subject to a $1,000 minimum.

NOTES

For More Information

Dreyfus/The Boston Company

Small Cap Growth Fund

A series of Dreyfus Investment Funds

SEC file number: 811-4813

More information on this fund is available free upon request, including the following:

Annual/Semiannual Report

Describes the fund’s performance, lists portfolio holdings and discusses recent market conditions, economic trends and investment strategies that significantly affected the fund’s performance during the last fiscal year. The fund’s annual and semi-annual reports are available at www.dreyfus.com.

Statement of Additional Information (SAI)

Provides more details about the fund and its policies. A current SAI is available at www.dreyfus.com and is on file with the Securities and Exchange Commission (SEC).The SAI is incorporated by reference (is legally considered part of this prospectus).

Portfolio Holdings

The fund will disclose its complete schedule of portfolio holdings, as reported on a month-end basis, at www.dreyfus.com, under Mutual Fund Center — Dreyfus Mutual Funds — Mutual Fund Total Holdings. The information will be posted with a one-month lag and will remain accessible until the fund files a report on Form N-Q or Form N-CSR for the period that includes the date as of which the information was current. In addition, fifteen days following the end of each calendar quarter, the fund will publicly disclose at www.dreyfus.com its complete schedule of portfolio holdings as of the end of such quarter.

A complete description of the fund’s policies and procedures with respect to the disclosure of the fund’s portfolio securities is available in the fund’s SAI.

To obtain information:

By telephone

Call your financial representative or 1-800-645-6561

By mail Write to:

The Dreyfus Family of Funds

144 Glenn Curtiss Boulevard

Uniondale, NY 11556-0144

By E-mail Send your request to info@dreyfus.com

On the Internet Text-only versions of certain fund documents can be viewed online or downloaded from:

SEC http://www.sec.gov

Dreyfus http://www.dreyfus.com

You can also obtain copies, after paying a duplicating fee, by visiting the SEC’s Public Reference Room in Washington, DC (for information, call 1-202-551-8090) or by E-mail request to publicinfo@sec.gov, or by writing to the SEC’s Public Reference Section, Washington, DC 20549-0102.

April 15, 2009

DREYFUS INVESTMENT FUNDS
- DREYFUS/THE BOSTON COMPANY SMALL CAP TAX-SENSITIVE EQUITY FUND

Supplement to Prospectus
dated February 1, 2009
As revised, April 15, 2009

Effective as of the close of business on July 6, 2007, Dreyfus/The Boston Company Small Cap Tax-Sensitive Equity Fund (the “Fund”) was closed to investments for new accounts, with certain exceptions. Effective July 1, 2009, the Fund’s closure policy will be modified.

Effective July 1, 2009, the following information supersedes and replaces any contrary information contained in the Fund’s Prospectus:

Participants in group employer retirement plans (and their successor plans), provided that the plan sponsor is approved by Dreyfus and has established the Fund as an investment option in the plan by the close of business on the Closing Date;
Wrap programs that have established the Fund as an investment option under the wrap program by the close of business on the Closing Date; and
The Fund’s primary portfolio managers and Fund Board members who do not have existing accounts.

Shareholders of the Fund as of the Closing Date may continue to make additional purchases and to reinvest dividends and capital gains into their existing Fund accounts.

6938S0409

Dreyfus/The Boston Company

Small Cap Tax-Sensitive Equity Fund

Seeks to maximize after-tax total return,

consisting of long-term growth of capital,

by investing in equity securities of small-cap U.S. companies

PROSPECTUS February 1, 2009

<R>As revised, April 15, 2009</R>


Contents


The Fund
Goal/Approach	1
Main Risks	2
Past Performance	4
Expenses	5
Management	6
Financial Highlights	8

Your Investment
Account Policies	9
Distributions and Taxes	14
Exchange Privilege	15
Account Instructions	16

For More Information
See back cover.

Note to Investors

The fund closed to new investors as of the close of business on July 6, 2007 (Closing Date). Shareholders of the fund as of the Closing Date may continue to buy shares in existing accounts. Shareholders whose accounts had a zero balance on or after the Closing Date are prohibited from reactivating the account or opening a new account. Investors who did not own shares of the fund at the Closing Date generally are not allowed to buy shares of the fund, except that new accounts may be established by: 1) participants in qualified retirement plans (including pension or profit sharing plans, pension funds, 401(k) plans and other benefit plans), if the plan sponsor included the fund as an investment option on, and the plan owned shares of the fund as of, the Closing Date; 2) certain institutional investors and financial professionals (including investment advisers, broker-dealers, banks and trust companies) who had expressed an interest in investing in the fund, either for themselves or on behalf of clients, by the Closing Date, if approved by an officer of Dreyfus Investment Funds; and 3) certain advisory clients of TBCAM or Dreyfus, and of their affiliates, upon the request of TBCAM or Dreyfus, provided that Dreyfus is able to effectively manage the additional assets in accordance with the fund’s investment strategy. Investors may be required to demonstrate eligibility to buy shares of the fund before an investment is accepted.

Dreyfus/The Boston Company Small Cap

Tax-Sensitive Equity Fund

Ticker Symbol SDCEX

The Fund

GOAL/APPROACH

The fund seeks to maximize after-tax total return, consisting of long-term growth of capital. This objective may be changed without shareholder approval. To pursue its goal, the fund normally invests at least 80% of its assets in equity securities of small-cap U.S. companies. The fund currently considers small-cap companies to be those with total market capitalizations, at the time of purchase, that are equal to or less than the total market capitalization of the largest company included in the Russell 2000^®Growth Index. This would correspond to companies with total market capitalizations equal to or less than $3.25 billion as of December 31, 2008.The fund’s equity investments may include common stocks, preferred stocks, convertible securities and warrants, including those purchased in initial public offerings (IPOs) or shortly thereafter.

The portfolio managers focus primarily on individual stock selection instead of trying to predict which industries or sectors will perform best and select particular investments for the fund by:

Using fundamental research to identify and follow companies considered to have attractive characteristics, such as strong business positions, solid cash flows and balance sheets, high quality management and high sustainable growth.
Investing in a company when the portfolio managers’ research indicates that the company will experience accelerating revenues and expanding operating margins, which may lead to rising estimate trends and favorable earnings surprises.

The fund uses the following tax-sensitive strategies, to the extent consistent with its investment goal, to reduce the impact of federal and state income taxes on the fund’s after-tax returns.

Minimizing sales of securities that result in capital gains.
If such a sale cannot be avoided, selling first the highest cost securities to reduce the amount of capital gain; also, preferring the sale of securities producing long-term gains to those producing short-term gains.
Selling underperforming securities to realize capital losses that can be offset against realized capital gains.

Concepts to understand

The Fund 1

MAIN RISKS

Market risk. The market value of a security may decline due to general market conditions that are not specifically related to a particular company, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates or adverse investor sentiment generally. A security’s market value also may decline because of factors that affect a particular industry or industries, such as labor shortages or increased production costs and competitive conditions within an industry.
Issuer risk. The value of a security may decline for a number of reasons which directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer’s products or services.
Small company risk. Small companies carry additional risks because their operating histories tend to be more limited, their earnings and revenues less predictable (and some companies may be experiencing significant losses), and their share prices more volatile than those of larger, more established companies.The shares of smaller companies tend to trade less frequently than those of larger, more established companies, which can adversely affect the pricing of smaller companies’ securities and the fund’s ability to sell them when the portfolio managers deem it appropriate.These companies may have limited product lines, markets and/or financial resources, or may depend on a limited management group. Some of the fund’s investments will rise and fall based on investor perception rather than economic factors. Other investments, including special situations, are made in anticipation of future products and services or events whose delay or cancellation could cause the stock price to drop.
Growth stock risk. Investors often expect growth companies to increase their earnings at a certain rate. If these expectations are not met, investors can punish the stocks inordinately, even if earnings do increase. In addition, growth stocks typically lack the dividend yield that may cushion stock prices in market downturns.
Market sector risk.The fund may significantly overweight or underweight certain companies, industries or market sectors, which may cause the fund’s performance to be more or less sensitive to developments affecting those companies, industries or sectors.
Foreign investment risk. To the extent the fund invests in foreign securities, its performance will be influenced by political, social and economic factors affecting investments in foreign companies. Special risks associated with investments in foreign companies include exposure to currency fluctuations, less liquidity, less developed or less efficient trading markets, lack of comprehensive company information, political and economic instability and differing auditing and legal standards.
Foreign currency risk. Investments in foreign currencies are subject to the risk that those currencies will decline in value relative to the U.S. dollar, or, in the case of hedged positions, that the U.S. dollar will decline relative to the currency being hedged. Currency rates in foreign countries may fluctuate significantly over short periods of time.A decline in the value of foreign currencies relative to the U.S. dollar will reduce the value of securities held by the fund and denominated in those currencies. Foreign currencies are also subject to risks caused by inflation, interest rates, budget deficits and low savings rates, political factors and government controls.
Emerging market risk. Emerging markets tend to be more volatile than the markets of more mature economies, and generally have less diverse and less mature economic structures and less stable political systems than those of developed countries. The securities of companies located in emerging markets are often subject to rapid and large changes in price.

Derivatives risk. The fund may use derivative instruments, such as options, futures and options on futures (including those relating to securities, indexes, foreign currencies and interest rates), and forward contracts. Certain derivatives may cause taxable income. A small investment in derivatives could have a potentially large impact on the fund’s performance. The use of derivatives involves risks different from, or possibly greater than, the risks associated with investing directly in the underlying assets. Derivatives can be highly volatile, illiquid and difficult to value, and there is the risk that changes in the value of a derivative held by the fund will not correlate with the underlying instruments or the fund’s other investments. Derivative instruments also involve the risk that a loss may be sustained as a result of the failure of the counterparty to the derivative instruments to make required payments or otherwise comply with the derivative instruments’ terms.
Leveraging risk. The use of leverage, such as engaging in reverse repurchase agreements, lending portfolio securities, entering into futures contracts or forward currency contracts and engaging in forward commitment transactions may magnify the fund’s gains or losses.
IPO risk. The fund may purchase securities of companies in IPOs.The prices of securities purchased in IPOs can be very volatile.The effect of IPOs on the fund’s performance depends on a variety of factors, including the number of IPOs the fund invests in relative to the size of the fund and whether and to what extent a security purchased in an IPO appreciates or depreciates in value. As a fund’s asset base increases, IPOs often have a diminished effect on such fund’s performance.

Other potential risks

Although the fund uses tax management strategies, the fund may sell and realize short-term gains on a stock if the stock appears to have peaked or is expected to decline in value, to increase diversification or to raise cash to pay expenses or meet shareholder redemption requests. In addition, some of the equity and fixed-income securities in the fund’s portfolio will regularly generate taxable income.

The fund may engage in short-term trading, which could produce higher transaction costs and taxable distributions and lower the fund’s after-tax performance.

The Fund 3

PAST PERFORMANCE

The bar chart and table shown illustrate the risks of investing in the fund. The bar chart shows the changes in the fund’s performance from year to year. The table compares the fund’s average annual total returns to those of the Russell 2000 Growth Index, a broad measure of small cap growth stock performance. All returns assume reinvestment of dividends and distributions. Of course, past performance (before and after taxes) is no guarantee of future results.

<R>

</R>

Year-by-year total returns as of 12/31 each year (%)

Fund shares


Best Quarter:	Q4 ‘99	+62.49%
Worst Quarter:	Q4 ‘08	-26.52%

* The fund’s performance in 1999 should be considered extraordinary

due to particularly favorable market conditions which are unlikely to

occur.


Average annual total returns as of 12/31/08

	1 Year	5 Years	10 Years

Fund
returns before taxes	-37.46%	-0.03%	4.10%

Fund
returns after taxes
on distributions	-37.46%	-1.25%	2.44%

Fund
returns after taxes
on distributions and
sale of fund shares	-24.35%	-0.02%	3.18%

Russell 2000
Growth Index
reflects no deduction for
fees, expenses or taxes	-38.54%	-2.35%	-0.76%

EXPENSES

Fee table

Annual fund operating expenses
(expenses paid from fund assets)
% of average daily net assets


Management fees	.80
Other expenses	.15
Total	.95


Expense example
1 Year	3 Years	5 Years	10 Years
$97	$303	$525	$1,166

Concepts to understand

Management fee: the fee paid to Dreyfus for managing the fund’s portfolio and assisting in all aspects of the fund’s operations.

The Fund 5

MANAGEMENT

Investment adviser

B. Randall Watts, Jr. and Todd Wakefield are the fund’s primary portfolio managers, positions they have held since September 2001 and July 2004, respectively. Mr.Watts is a senior vice president and is the lead portfolio manager for the U.S. small-cap and micro-cap growth investment team at TBCAM, where he has been employed since 2003. He is also responsible for conducting research covering the technology and industrial sectors. Mr. Wakefield is a vice president and is a portfolio manager for the U.S. small-cap growth and small-to mid-cap growth strategies atTBCAM, where he has been employed since 2003. He is also responsible for conducting research covering the consumer services and energy sectors. Mr. Watts and Mr. Wakefield have been employed by Dreyfus since December 2008. As dual employees of Dreyfus and TBCAM, Mr.Watts and Mr.Wakefield manage the fund as employees of Dreyfus but use TBCAM’s proprietary investment process.

Distributor

Code of ethics

The Fund 7

FINANCIAL HIGHLIGHTS


		Year Ended September 30,
	2008	2007	2006	2005	2004
Net Asset Value, Beginning of Year	$43.15	$42.27	$42.35	$34.71	$29.58
From Operations:
Net investment income (loss)^(a)	(0.07)	(0.07)	(0.08)	(0.10)	(0.24)
Net realized and unrealized gains (loss) on investments	(6.42)^(b)	8.07^(b)	3.08	7.74	5.37^(b)
Total from operations	(6.49)	8.00	3.00	7.64	5.13
Less Distributions to Shareholders:
From net realized gains on investments	(3.07)	(7.12)	(3.08)	—	—
Total distributions to shareholders	(3.07)	(7.12)	(3.08)	—	—
Net Asset Value, End of Year	$33.59	$43.15	$42.27	$42.35	$34.71
Total Return	(15.99%)	20.79%	7.49%	22.01%	17.34%
Ratios/Supplemental Data:
Expenses (to average daily net assets)	0.95%	0.96%	0.99%	0.99%	1.03%
Net Investment Income (Loss) (to average daily net assets)	(0.19%)	(0.17%)	(0.18%)	(0.26%)	(0.71%)
Portfolio Turnover	209%	170%	169%	137%	150%
Net Assets, End of Year (000’s omitted)	$303,246	$316,479	$160,552	$160,035	$120,372

(a) Calculated based on average shares outstanding.

(b) Amounts include litigation proceeds received by the fund of $0.01 for the year ended September 30, 2008, $0.04 for the year ended September 30, 2007 and

$0.03 for the year ended September 30, 2004.

Your Investment

ACCOUNT POLICIES

Shares of the fund are available only to limited types of investors, and may be purchased by:

bank trust departments, trust companies and insurance companies that have entered into agreements with the fund’s distributor to offer fund shares to their clients
institutional investors acting in a fiduciary, advisory, agency, custodial or similar capacity for qualified or non-qualified employee benefit plans, including pension, profit-sharing and other deferred compensation plans, whether established by corporations, partnerships, non-profit entities, trade or labor unions, or state and local governments, and IRAs set up under Simplified Employee Pension Plans that have entered into agreements with the fund’s distributor to offer fund shares to such plans
law firms or attorneys acting as trustees or executors/administrators
foundations and endowments that make an initial investment in the fund of at least $1 million
sponsors of college savings plans that qualify for tax-exempt treatment under Section 529 of the Internal Revenue Code, that maintain an omnibus account with the fund and do not require shareholder tax reporting or 529 account support responsibilities from the fund’s distributor
advisory fee-based accounts offered through financial intermediaries who, depending on the structure of the selected advisory platform, make fund shares available

You pay no sales charges to invest in the fund. Your price for fund shares is the fund’s net asset value per share (NAV), which is generally calculated as of the close of trading on the New York Stock Exchange (usually 4:00 p.m. Eastern time) on days the exchange is open for regular business.

Your order will be priced at the next NAV calculated after your order is received in proper form by the fund’s transfer agent or other authorized entity.

When calculating its NAV,the fund’s investments are valued on the basis of market quotations or official closing prices. If market quotations or official closing prices are not readily available, or are determined not to reflect accurately fair value (such as when the value of a security has been materially affected by events occurring after the close of the exchange or market on which the security is principally traded (for example, a foreign exchange or market), but before the fund calculates its NAV), the fund may value those investments at fair value as determined in accordance with procedures approved by the fund’s board. Fair value of investments may be determined by the fund’s board, its pricing committee or its valuation committee in good faith using such information as it deems appropriate under the circumstances. Fair value of foreign equity securities may be determined with the assistance of a pricing service using correlations between the movement of prices of foreign securities and indexes of domestic securities and other appropriate indicators, such as closing market prices of relevant ADRs and futures contracts. Using fair value to price securities may result in a value that is different from a security’s most recent closing price and from the prices used by other mutual funds to calculate their net asset values. Forward currency contracts will be valued at the current cost of offsetting the contract. Foreign securities may trade on days when the fund does not calculate its NAV and thus may affect the fund’s NAV on days when investors have no access to the fund.

Your Investment 9

ACCOUNT POLICIES (continued)

Concept to understand

Net asset value (NAV): a mutual fund’s share price on a given day. A fund’s NAV is calculated by dividing the value of its net assets by the number of its existing shares outstanding.


Minimum investments^†
	Initial	Additional
Regular accounts	$1,000	$100

<R></R>

All investments must be in U.S. dollars. Third-party checks, cash, travelers' checks or money orders will not be accepted. You may be charged a fee for any check that does not clear.

^†The minimum initial investment for foundations and endowments is

$1 million.

<R></R>

Selling shares

Before selling shares recently purchased by check, please note that:

if you send a written request to sell such shares, the fund may delay sending the proceeds for up to eight business days following the purchase of those shares
the fund will not process wire or telephone redemption requests for up to eight business days following the purchase of those shares


Limitations on selling shares by phone

Proceeds	Minimum	Maximum
sent by	phone	phone

Check	no minimum	$250,000 per day

Wire	$1,000	$500,000 for joint
		accounts every 30 days/
		$20,000 per day

Written sell orders

Some circumstances require written sell orders along with signature guarantees. These include:

amounts of $10,000 or more on accounts whose address has been changed within the last 30 days
requests to send the proceeds to a different payee or address

Written sell orders of $100,000 or more must also be signature guaranteed.

Your Investment 11

ACCOUNT POLICIES (continued)

General policies

The fund reserves the right to:

change or discontinue its exchange privilege, or temporarily suspend the privilege during unusual market conditions
change its minimum or maximum investment amounts
delay sending out redemption proceeds for up to seven days (generally applies only during unusual market conditions or in cases of very large redemptions or excessive trading)
“redeem in kind,” or make payments in securities rather than cash, if the amount redeemed is large enough to affect fund operations (for example, if it exceeds 1% of the fund’s assets)
refuse any purchase or exchange request, including those from any individual or group who, in Dreyfus’ view, is likely to engage in frequent trading

Third-party investments

Small account policy

If your account falls below $500, the fund may ask you to increase your balance. If it is still below $500 after 30 days, the fund may close your account and send you the proceeds.

Your Investment 13

DISTRIBUTIONS AND TAXES

The tax status of your distributions will be detailed in your annual tax statement from the fund. Because everyone’s tax situation is unique, please consult your tax advisor before investing.

EXCHANGE PRIVILEGE

You can exchange shares worth $500 or more

(no minimum for retirement accounts) of the fund for Class I shares of other Dreyfus funds or for shares of certain other Dreyfus funds. You can request your exchange in writing or by phone. Be sure to read the current prospectus for any fund into which you are exchanging before investing. Any new account established through an exchange will have the same privileges as your original account (as long as they are available).There is currently no fee for exchanges, although you may be charged a sales load when exchanging into any fund that has one.

Your Investment 15

For information and other assistance, call toll free
in the U.S. 1-800-645-6561.

Outside the U.S. 516-794-5452.

Make checks payable to: The Dreyfus Family of Funds.

NOTES

For More Information

Dreyfus/The Boston Company Small Cap

Tax-Sensitive Equity Fund

A series of Dreyfus Investment Funds

SEC file number: 811-4813

More information on this fund is available free upon request, including the following:

Annual/Semiannual Report

Statement of Additional Information (SAI)

Portfolio Holdings

A complete description of the fund’s policies and procedures with respect to the disclosure of the fund’s portfolio securities is available in the fund’s SAI.

To obtain information:

By telephone

Call your financial representative or 1-800-645-6561

By mail Write to:

The Dreyfus Family of Funds

144 Glenn Curtiss Boulevard

Uniondale, NY 11556-0144

By E-mail Send your request to info@dreyfus.com

On the Internet Text-only versions of certain fund documents can be viewed online or downloaded from:

SEC http://www.sec.gov

Dreyfus http://www.dreyfus.com

April 15, 2009

DREYFUS INVESTMENT FUNDS
- DREYFUS/THE BOSTON COMPANY SMALL CAP VALUE FUND

Supplement to Prospectus
dated February 1, 2009
As revised, April 15, 2009

Effective as of the close of business on August 31, 2006, Dreyfus/The Boston Company Small Cap Value Fund (the “Fund”) was closed to investments for new accounts, with certain exceptions. Effective July 1, 2009, the Fund’s closure policy will be modified.

Effective July 1, 2009, the following information supersedes and replaces any contrary information contained in the Fund’s Prospectus:

The Fund closed to new investors as of the close of business on August 31, 2006 (the “Closing Date”). Investors who did not own shares of the Fund at the Closing Date generally are not permitted to buy shares of the Fund, except that new accounts may be established by:

Participants in group employer retirement plans (and their successor plans), provided that the plan sponsor is approved by Dreyfus and has established the Fund as an investment option in the plan by the close of business on the Closing Date;
Wrap programs that have established the Fund as an investment option under the wrap program by the close of business on the Closing Date; and
The Fund’s primary portfolio managers and Fund Board members who do not have existing accounts.

Shareholders of the Fund as of the Closing Date may continue to make additional purchases and to reinvest dividends and capital gains into their existing Fund accounts.

6944S0409

Dreyfus/The Boston Company

Small Cap Value Fund

Seeks long-term growth of capital

by investing in equity securities of

small-cap U.S. companies

PROSPECTUS February 1, 2009

<R>As revised, April 15, 2009</R>


Contents


The Fund
Goal/Approach	1
Main Risks	2
Past Performance	4
Expenses	5
Management	6
Financial Highlights	8

Your Investment
Account Policies	9
Distributions and Taxes	14
Exchange Privilege	15
Account Instructions	16

For More Information
See back cover.

Note to Investors

The fund closed to new investors as of the close of business on August 31, 2006 (Closing Date). Shareholders of the fund as of the Closing Date may continue to buy shares in existing accounts. Shareholders whose accounts had a zero balance on or after the Closing Date are prohibited from reactivating the account or opening a new account. Investors who did not own shares of the fund at the Closing Date generally are not allowed to buy shares of the fund, except that new accounts may be established by: 1) participants in qualified retirement plans (including pension or profit sharing plans, pension funds, 401(k) plans and other benefit plans), if the plan sponsor included the fund as an investment option on, and the plan owned shares of the fund as of, the Closing Date; 2) certain institutional investors and financial professionals (including investment advisers, broker-dealers, banks and trust companies) who expressed an interest in investing in the fund, either for themselves or on behalf of clients, by the Closing Date, if approved by an officer of Dreyfus Investment Funds; and 3) certain advisory clients of TBCAM or Dreyfus, and of their affiliates, upon the request of TBCAM or Dreyfus, provided that Dreyfus is able to effectively manage the additional assets in accordance with the fund’s investment strategy. Investors may be required to demonstrate eligibility to buy shares of the fund before an investment is accepted.

The Fund

Dreyfus/The Boston Company Small Cap Value Fund

Ticker Symbol STSVX

GOAL/APPROACH

The portfolio managers use a variety of screening methods to identify small cap companies that might be attractive investments. Once attractive investments have been identified, the portfolio managers then use a consistent three-step fundamental research process to evaluate the stocks, consisting of:

Valuation: to identify small cap companies that are considered to be attractively priced relative to their earnings potential;
Fundamentals: to verify the strength of the underlying business position; and
Catalyst: to identify a specific event that has the potential to cause the stocks to appreciate in value.

The portfolio managers focus primarily on individual stock selection instead of trying to predict which industries or sectors will perform best. The stock selection process is designed to produce a diversified portfolio of companies that the portfolio managers believe are undervalued relative to expected business growth.

Concepts to understand

Small-cap companies: generally new and often entrepreneurial companies. Small-cap companies tend to grow faster than large-cap companies but frequently are more volatile, more vulnerable to major setbacks, and have a higher failure rate than larger companies.

Value companies: companies that appear underpriced according to certain financial measurements of their intrinsic worth or business prospects (such as price-to-earnings, price-to-sales or price-to-cash-flow ratios). Because a stock can remain undervalued for years, value investors often look for factors that could trigger a rise in price.

Russell 2000 Value Index: an unmanaged index, which is the fund’s benchmark index, that measures the performance of those Russell 2000 companies (the 2000 smallest companies in the Russell 3000^®Index, which represents approximately 10% of the total market capitalization of the Russell 3000 Index) with lower price-to-book ratios and lower forecasted growth values.

The Fund 1

MAIN RISKS

Market risk. The market value of a security may decline due to general market conditions that are not specifically related to a particular company, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates or adverse investor sentiment generally. A security’s market value also may decline because of factors that affect a particular industry or industries, such as labor shortages or increased production costs and competitive conditions within an industry.
Issuer risk.The value of a security may decline for a number of reasons which directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer’s products or services.
Small company risk. Small companies carry additional risks because their operating histories tend to be more limited, their earnings and revenues less predictable (and some companies may be experiencing significant losses), and their share prices more volatile than those of larger, more established companies. The shares of smaller companies tend to trade less frequently than those of larger, more established companies, which can adversely affect the pricing of smaller companies’ securities and the fund’s ability to sell them when the portfolio managers deem it appropriate. These companies may have limited product lines, markets and/or financial resources, or may depend on a limited management group. Some of the fund’s investments will rise and fall based on investor perception rather than economic factors. Other investments, including special situations, are made in anticipation of future products and services or events whose delay or cancellation could cause the stock price to drop.
Value stock risk. Value stocks involve the risk that they may never reach what the portfolio managers believe is their full market value, either because the market fails to recognize the stock’s intrinsic worth or the portfolio managers mis-gauged that worth. They also may decline in price, even though in theory they are already undervalued. Because different types of stocks tend to shift in and out of favor depending on market and economic conditions, the fund’s performance may sometimes be lower or higher than that of other types of funds (such as those emphasizing growth stocks).
Market sector risk. The fund may significantly overweight or underweight certain companies, industries or market sectors, which may cause the fund’s performance to be more or less sensitive to developments affecting those companies, industries or sectors.
Foreign investment risk. To the extent the fund invests in foreign securities, its performance will be influenced by political, social and economic factors affecting investments in foreign companies. Special risks associated with investments in foreign companies include exposure to currency fluctuations, less liquidity, less developed or less efficient trading markets, lack of comprehensive company information, political and economic instability and differing auditing and legal standards.
Foreign currency risk. Investments in foreign currencies are subject to the risk that those currencies will decline in value relative to the U.S. dollar, or, in the case of hedged positions, that the U.S. dollar will decline relative to the currency being hedged. Currency rates in foreign countries may fluctuate significantly over short periods of time. A decline in the value of foreign currencies relative to the U.S. dollar will reduce the value of securities held by the fund and denominated in those currencies. Foreign currencies are also subject to risks caused by inflation, interest rates, budget deficits and low savings rates, political factors and government controls.

Emerging market risk. Emerging markets tend to be more volatile than the markets of more mature economies, and generally have less diverse and less mature economic structures and less stable political systems than those of developed countries. The securities of companies located in emerging markets are often subject to rapid and large changes in price.
Derivatives risk. The fund may use derivative instruments, such as options, futures and options on futures (including those relating to securities, indexes, foreign currencies and interest rates), and forward contracts. A small investment in derivatives could have a potentially large impact on the fund’s performance. The use of derivatives involves risks different from, or possibly greater than, the risks associated with investing directly in the underlying assets. Derivatives can be highly volatile, illiquid and difficult to value, and there is the risk that changes in the value of a derivative held by the fund will not correlate with the underlying instruments or the fund’s other investments. Derivative instruments also involve the risk that a loss may be sustained as a result of the failure of the counterparty to the derivative instruments to make required payments or otherwise comply with the derivative instruments’ terms.
Leveraging risk. The use of leverage, such as engaging in reverse repurchase agreements, lending portfolio securities, entering into futures contracts or forward currency contracts and engaging in forward commitment transactions may magnify the fund’s gains or losses.
IPO risk. The fund may purchase securities of companies in IPOs.The prices of securities purchased in IPOs can be very volatile.The effect of IPOs on the fund’s performance depends on a variety of factors, including the number of IPOs the fund invests in relative to the size of the fund and whether and to what extent a security purchased in an IPO appreciates or depreciates in value.As a fund’s asset base increases, IPOs often have a diminished effect on such fund’s performance.

Other potential risks

The fund may engage in short-term trading, which could produce higher transaction costs and taxable distributions and lower the fund’s after-tax performance.

The fund may lend its portfolio securities to brokers, dealers and other financial institutions. In connection with such loans the fund will receive collateral from the borrower equal to at least 100% of the value of the loaned securities. If the borrower of the securities fails financially, there could be delays in recovering the loaned securities or exercising rights to the collateral.

The Fund 3

PAST PERFORMANCE

The bar chart and table shown illustrate the risks of investing in the fund. The bar chart shows the changes in the fund’s performance from year to year. The table compares the fund’s average annual total returns to those of the Russell 2000 Value Index, a broad measure of small cap value stock per formance. All returns assume reinvestment of dividends and distributions. Of course, past perfor mance (before and after taxes) is no guarantee of future results.

<R>

</R>

Year-by-year total returns as of 12/31 each year (%)

Fund shares


Best Quarter:	Q2 ’03	+22.52%
Worst Quarter:	Q4 ’08	-25.13%


Average annual total returns as of 12/31/08

			Since Inception
	1 Year	5 Years	(2/1/00)

Fund
returns before taxes	-32.04%	1.54%	9.43%

Fund
returns after taxes
on distributions	-32.17%	0.04%	8.01%

Fund
returns after taxes
on distributions and
sale of fund shares	-20.64%	1.09%	7.93%

Russell 2000
Value Index
reflects no deduction for
fees, expenses or taxes	-28.92%	0.27%	7.37%

EXPENSES

Fee table

Annual fund operating expenses
(expenses paid from fund assets)
% of average daily net assets


Management fees			0.80
Other expenses			0.13
Total			0.93

Expense example
1 Year	3 Years	5 Years	10 Years
$95	$296	$515	$1,143

Concepts to understand

Management fee: the fee paid to Dreyfus for managing the fund’s portfolio and assisting in all aspects of the fund’s operations.

The Fund 5

MANAGEMENT

Investment adviser

Joseph M. Corrado, CFA, and Stephanie K. Brandaleone, CFA, are the fund’s primary portfolio managers, positions they have held since February 2000. Mr. Corrado is a senior vice president and is the lead portfolio manager for the U.S. small-cap value and small/midcap value strategy at TBCAM, where he has been employed since 2003. He is also responsible for conducting research covering the consumer, energy, financial and industrial sectors. Ms. Brandaleone is a vice president, portfolio manager for the U.S. small-cap value and small/midcap value strategy and investment research analyst at TBCAM, where she has been employed since 2003. Mr. Corrado and Ms. Brandaleone have been employed by Dreyfus since December 2008.As dual employees of Dreyfus and TBCAM, Mr. Corrado and Ms. Brandaleone manage the fund as employees of Dreyfus but use TBCAM’s proprietary investment process.

Distributor

Code of ethics

The Fund 7

FINANCIAL HIGHLIGHTS


		Year Ended September 30,
	2008	2007	2006	2005	2004
Net Asset Value, Beginning of Year	$25.26	$23.70	$22.55	$21.91	$18.49
From Investment Operations:
Net investment income (loss)^(a)	0.18	0.16	0.09	0.02	(0.05)
Net realized and unrealized gains (loss) on investments	(3.95)	2.48	2.58	4.29	5.27
Total from operations	(3.77)	2.64	2.67	4.31	5.22
Less Distributions to Shareholders:
From net investment income	(0.19)	(0.09)	(0.03)	—	—
From net realized gains on investments	(1.45)	(0.99)	(1.49)	(3.67)	(1.80)
Total distributions to shareholders	(1.64)	(1.08)	(1.52)	(3.67)	(1.80)
Net Asset Value, End of Year	$19.85	$25.26	$23.70	$22.55	$21.91
Total Return	(15.38%)	11.18%	12.42%	21.34%	29.92%
Ratios/Supplemental data:
Expenses (to average daily net assets)	0.93%	0.90%^(b)	0.94%^(b)	1.05%^(b)	1.18%^(b)
Net Investment Income (Loss) (to average daily net assets)	0.85%	0.61%	0.40%	0.08%	(0.24%)
Portfolio Turnover	73%	67%^(c)	60%^(c)	70%^(c)	123%^(c)
Net Assets, End of Year (000’s omitted)	$504,373	$829,957 $539,560 $189,647			$61,182

(a)Calculated based on average shares outstanding.

(b)For the period October 1, 2006 to September 19, 2007 and for the fiscal years ended September 30, 2004-2006, the ratio includes the fund’s share of TBC Small

CapValue Portfolio’s (Portfolio) allocated expenses.

(c) On September 19, 2007, the fund, which had owned 100% of the Portfolio on such date, withdrew entirely from the Portfolio and received the Portfolio’s securities

and cash in exchange for its interests in the Portfolio. Effective September 20, 2007, the fund began investing directly in the securities in which the Portfolio had

invested. Portfolio turnover represents investment activity of both the fund and the Portfolio for the year.The amounts shown for 2004-2006 are the ratios for the

Portfolio.

Your Investment

ACCOUNT POLICIES

Shares of the fund are available only to limited types of investors, and may be purchased by:

bank trust departments, trust companies and insurance companies that have entered into agreements with the fund’s distributor to offer fund shares to their clients
institutional investors acting in a fiduciary, advisory, agency, custodial or similar capacity for qualified or non-qualified employee benefit plans, including pension, profit-sharing and other deferred compensation plans, whether established by corporations, partnerships, non-profit entities, trade or labor unions, or state and local governments, and IRAs set up under Simplified Employee Pension Plans that have entered into agreements with the fund’s distributor to offer fund shares to such plans
law firms or attorneys acting as trustees or executors/administrators
foundations and endowments that make an initial investment in the fund of at least $1 million
sponsors of college savings plans that qualify for tax-exempt treatment under Section 529 of the Internal Revenue Code, that maintain an omnibus account with the fund and do not require shareholder tax reporting or 529 account support responsibilities from the fund’s distributor
advisory fee-based accounts offered through financial intermediaries who, depending on the structure of the selected advisory platform, make fund shares available

Your order will be priced at the next NAV calculated after your order is received in proper form by the fund’s transfer agent or other authorized entity.

Concept to understand

Net asset value (NAV): a mutual fund’s share price on a given day. A fund’s NAV is calculated by dividing the value of its net assets by the number of its existing shares outstanding.

Your Investment 9

ACCOUNT POLICIES (continued)


Minimum investments^†
	Initial	Additional
Regular accounts	$1,000	$100

<R></R>

All investments must be in U.S. dollars. Third-party checks, cash, travelers’ checks or money orders will not be accepted. You may be charged a fee for any check that does not clear.

^†The minimum initial investment for foundations and endowments is

$1 million.

<R></R>

Selling shares

Before selling shares recently purchased by check, please note that:

if you send a written request to sell such shares, the fund may delay sending the proceeds for up to eight business days following the purchase of those shares
the fund will not process wire or telephone redemption requests for up to eight business days following the purchase of those shares


Limitations on selling shares by phone

Proceeds	Minimum	Maximum
sent by	phone	phone

Check	no minimum	$250,000 per day

Wire	$1,000	$500,000 for joint
		accounts every 30 days/
		$20,000 per day

Written sell orders

Some circumstances require written sell orders along with signature guarantees. These include:

amounts of $10,000 or more on accounts whose address has been changed within the last 30 days
requests to send the proceeds to a different payee or address

Written sell orders of $100,000 or more must also be signature guaranteed.

Your Investment 11

ACCOUNT POLICIES (continued)

General policies

The fund reserves the right to:

change or discontinue its exchange privilege, or temporarily suspend the privilege during unusual market conditions
change its minimum or maximum investment amounts
delay sending out redemption proceeds for up to seven days (generally applies only during unusual market conditions or in cases of very large redemptions or excessive trading)
“redeem in kind,” or make payments in securities rather than cash, if the amount redeemed is large enough to affect fund operations (for example, if it exceeds 1% of the fund’s assets)
refuse any purchase or exchange request, including those from any individual or group who, in Dreyfus’ view, is likely to engage in frequent trading

Certain retirement plans and intermediaries that maintain omnibus accounts with the fund may have developed policies designed to control frequent trading that may differ from the fund’s policy. At its sole discretion, the fund may permit such intermediaries to apply their own frequent trading policy. If you are investing in fund shares through an intermediary (or in the case of a retirement plan, your plan sponsor), please contact the intermediary for information on the frequent trading policies applicable to your account.

To the extent that the fund significantly invests in foreign securities traded on markets that close before the fund calculates its NAV, events that influence the value of these foreign securities may occur after the close of these foreign markets and before the fund calculates its NAV. As a result, certain investors may seek to trade fund shares in an effort to benefit from their understanding of the value of these foreign securities at the time the fund calculates its NAV (referred to as price arbi-trage).This type of frequent trading may dilute the value of fund shares held by other shareholders.The fund has adopted procedures designed to adjust closing market prices of foreign equity securities under certain circumstances to reflect what it believes to be their fair value.

Third-party investments

Small account policy

If your account falls below $500, the fund may ask you to increase your balance. If it is still below $500 after 30 days, the fund may close your account and send you the proceeds.

Your Investment 13

DISTRIBUTIONS AND TAXES

The tax status of your distributions will be detailed in your annual tax statement from the fund. Because everyone’s tax situation is unique, please consult your tax advisor before investing.

EXCHANGE PRIVILEGE

Your Investment 15

For information and other assistance, call toll free in the U.S.

1-800-645-6561.

Outside the U.S. 516-794-5452.

Make checks payable to: The Dreyfus Family of Funds

NOTES

For More Information

Dreyfus/The Boston Company

Small Cap Value Fund

A series of Dreyfus Investment Funds

SEC file number: 811-4813

More information on this fund is available free upon request, including the following:

Annual/Semiannual Report

Describes the fund’s performance, lists portfolio holdings and discusses recent market conditions, economic trends and investment strategies that significantly affected the fund’s performance during the last fiscal year.The fund’s annual and semi-annual reports are available at www.dreyfus.com.

Statement of Additional Information (SAI)

Portfolio Holdings

The fund will disclose its complete schedule of portfolio holdings, as reported on a month-end basis, at www.dreyfus.com, under Mutual Fund Center – Dreyfus Mutual Funds – Mutual Fund Total Holdings.The information will be posted with a one-month lag and will remain accessible until the fund files a report on Form N-Q or Form N-CSR for the period that includes the date as of which the information was current. In addition, fifteen days following the end of each calendar quarter, the fund will publicly disclose at www.dreyfus.com its complete schedule of portfolio holdings as of the end of such quarter.

A complete description of the fund’s policies and procedures with respect to the disclosure of the fund’s portfolio securities is available in the fund’s SAI.

To obtain information:

By telephone

Call your financial representative or 1-800-645-6561

By mail Write to:

The Dreyfus Family of Funds

144 Glenn Curtiss Boulevard

Uniondale, NY 11556-0144

By E-mail Send your request to info@dreyfus.com

On the Internet Text-only versions of certain fund documents can be viewed online or downloaded from:

SEC http://www.sec.gov

Dreyfus http://www.dreyfus.com

Dreyfus/The Boston Company

International Core Equity Fund

Seeks long-term growth of capital by investing

in equity securities of foreign companies

PROSPECTUS February 1, 2009

<R>As revised, April 15, 2009</R>


Contents


The Fund
Goal/Approach	1
Main Risks	2
Past Performance	4
Expenses	5
Management	6
Financial Highlights	8

Your Investment
Account Policies	9
Distributions and Taxes	15
Exchange Privilege	16
Account Instructions	17

For More Information
See back cover.

The Fund

Dreyfus/The Boston Company

International Core Equity Fund

Ticker Symbol SDIEX

GOAL/APPROACH

The fund seeks long-term growth of capital. To pursue this goal, the fund normally invests at least 80% of its assets in equity securities of companies represented in the Morgan Stanley Capital International Europe, Australasia and Far East (EAFE) Index and Canada. The fund’s equity investments may include common stocks, preferred stocks, convertible securities and warrants, including those purchased in initial public offerings (IPOs) or shortly thereafter. The fund also may invest up to 20% of its assets in high grade fixed-income securities (i.e., rated A or better or the unrated equivalent) of any maturity or duration, and may invest up to 5% of its assets in fixed-income securities in the lowest long-term investment grade category (i.e., rated Baa-/BBB- or the unrated equivalent).

The fund intends to invest in a broad range of (and in any case at least five different) countries. The fund is not required to invest in every country represented in, or to match the country weightings of, the EAFE Index.The fund may invest up to 25% of its assets in securities of issuers located in emerging market countries, but no more than 5% of its assets may be invested in issuers located in any one emerging market country.

The fund invests in stocks that appear to be undervalued (as measured by their price/earnings ratios) and that may have value and/or growth characteristics.The portfolio manager employs a bottom-up investment approach which emphasizes individual stock selection.

Stock selection —The portfolio manager uses proprietary quantitative models and traditional qualitative analysis to identify attractive stocks with low relative price multiples and positive trends in earnings forecasts.
Country allocations — The portfolio manager seeks generally to allocate country weights in accordance with the EAFE Index, but deviations from the EAFE Index country weightings may occur.
Sector and industry allocations — The portfolio manager uses the sector and industry allocations of the EAFE Index as a guide, but allocations may differ from those of the EAFE Index.

The fund’s stock selection process is designed to produce a diversified portfolio that, relative to the EAFE Index, frequently has a below-average price/earnings ratio and an above-average earnings growth trend.

The fund may, but is not required to, use derivatives, such as futures, options and forward contracts, as a substitute for investing directly in an underlying asset or currency, to increase returns, to manage currency risk, or as part of a hedging strategy. Generally, the fund would enter into equity index futures contracts based primarily on the indices of the countries included in the EAFE Index and Canada.

Concept to understand

EAFE Index: is a free float-adjusted market capitalization index that is designed to measure the equity market performance of developed markets, excluding the United States and Canada. As of December 31, 2008, the EAFE Index consisted of the following 21 developed market country indices: Australia, Austria, Belgium, Denmark, Finland, France, Germany, Greece, Hong Kong, Ireland, Italy, Japan, the Netherlands, New Zealand, Norway, Portugal, Singapore, Spain, Sweden, Switzerland, and the United Kingdom. While the EAFE Index excludes stocks of companies located in Canada or emerging markets, the fund may invest in such stocks.

The Fund 1

MAIN RISKS

Foreign investment risk. The fund’s performance will be influenced by political, social and economic factors affecting investments in foreign companies. Special risks associated with investments in foreign companies include exposure to currency fluctuations, less liquidity, less developed or less efficient trading markets, lack of comprehensive company information, political and economic instability and differing auditing and legal standards.
Foreign currency risk. Investments in foreign currencies are subject to the risk that those currencies will decline in value relative to the U.S. dollar, or, in the case of hedged positions, that the U.S. dollar will decline relative to the currency being hedged. Currency rates in foreign countries may fluctuate significantly over short periods of time.A decline in the value of foreign currencies relative to the U.S. dollar will reduce the value of securities held by the fund and denominated in those currencies. Foreign currencies are also subject to risks caused by inflation, interest rates, budget deficits and low savings rates, political factors and government controls.
Emerging market risk. Emerging markets tend to be more volatile than the markets of more mature economies, and generally have less diverse and less mature economic structures and less stable political systems than those of developed countries. The securities of companies located in emerging markets are often subject to rapid and large changes in price.
Market risk. The market value of a security may decline due to general market conditions that are not specifically related to a particular company, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates or adverse investor sentiment generally. A security’s market value also may decline because of factors that affect a particular industry or industries, such as labor shortages or increased production costs and competitive conditions within an industry.
Issuer risk.The value of a security may decline for a number of reasons which directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer’s products or services.
Value/Growth stock risk. By investing in a mix of value and growth companies, the fund assumes the risks of both. Because different types of stocks tend to shift in and out of favor depending on market and economic conditions, the fund’s performance may sometimes be lower or higher than that of other types of funds. Value stocks involve the risk that they may never reach what the portfolio manager believes is their full market value, either because the market fails to recognize the stock’s intrinsic worth or the portfolio manager misgauged that worth. They also may decline in price, even though in theory they are already undervalued. Investors often expect growth companies to increase their earnings at a certain rate. If these expectations are not met, investors can punish the stocks inordinately, even if earnings do increase. In addition, growth stocks typically lack the dividend yield that can cushion stock prices in market downturns.

Market sector risk. The fund may significantly overweight or underweight certain companies, industries or market sectors, which may cause the fund’s performance to be more or less sensitive to developments affecting those companies, industries or sectors.
Derivatives risk. The fund may use derivative instruments, such as options, futures and options on futures (including those relating to securities, indexes, foreign currencies and interest rates), and forward contracts. A small investment in derivatives could have a potentially large impact on the fund’s performance. The use of derivatives involves risks different from, or possibly greater than, the risks associated with investing directly in the underlying assets. Derivatives can be highly volatile, illiquid and difficult to value, and there is the risk that changes in the value of a derivative held by the fund will not correlate with the underlying instruments or the fund’s other investments. Derivative instruments also involve the risk that a loss may be sustained as a result of the failure of the counterparty to the derivative instruments to make required payments or otherwise comply with the derivative instruments’ terms.
Leveraging risk. The use of leverage, such as lending portfolio securities, entering into futures contracts or forward currency contracts, entering into reverse repurchase agreements and engaging in forward commitment transactions, may magnify the fund’s gains or losses.
IPO risk. The fund may purchase securities of companies in IPOs.The prices of securities purchased in IPOs can be very volatile.The effect of IPOs on the fund’s performance depends on a variety of factors, including the number of IPOs the fund invests in relative to the size of the fund and whether and to what extent a security purchased in an IPO appreciates or depreciates in value.As a fund’s asset base increases, IPOs often have a diminished effect on such fund’s performance.

Other potential risks

The fund may engage in short-term trading, which could produce higher transaction costs and taxable distributions and lower the fund’s after-tax performance.

The Fund 3

PAST PERFORMANCE

<R>

</R>

Year-by-year total returns as of 12/31 each year (%)


Best Quarter:	Q2 ’03	+17.62%
Worst Quarter:	Q4 ’08	-23.21%


Average annual total returns as of 12/31/08

	1 Year	5 Years	10 Years

Fund
returns before taxes	-47.80%	0.74%	3.17%

Fund
returns after taxes
on distributions	-47.74%	-0.66%	1.81%

Fund
returns after taxes
on distributions and
sale of fund shares	-30.66%	2.03%	3.06%

EAFE Index
reflects no deduction for
fees, expenses or taxes	-43.38%	1.66%	0.80%

EXPENSES

As an investor, you pay certain fees and expenses in connection with the fund, which are described in the table below. Shareholder transaction fees are paid from your account. Annual fund operating expenses are paid out of fund assets, so their effect is included in the share price.The fund has no sales charge (load) or Rule 12b-1 distribution fees.


Fee table

Shareholder transaction fees
(fees paid from your account)

Maximum redemption fee	2.00
% of transaction amount charged
only when selling shares you have
owned for less than 60 days

Annual fund operating expenses
(expenses paid from fund assets)
% of average daily net assets
Management fees	0.80
Other expenses	0.27
Total	1.07


Expense example
1 Year	3 Years	5 Years	10 Years
$109	$340	$590	$1,306

Concepts to understand

Management fee: the fee paid to Dreyfus for managing the fund’s portfolio and assisting in all aspects of the fund’s operations.

For the fiscal year ended September 30, 2008, a portion of the fund’s expenses were waived or reimbursed, reducing the fund’s total annual operating expenses from 1.07% to .87%. This waiver is voluntary and may be terminated at any time.

The Fund 5

MANAGEMENT

Investment adviser

The investment adviser for the fund is Dreyfus, 200 Park Avenue, NewYork, NewYork 10166. Founded in 1947, Dreyfus manages approximately $354 billion in approximately 200 mutual fund portfolios. The fund has agreed to pay Dreyfus an investment advisory fee at the annual rate of 0.80% of the fund’s average daily net assets up to $500 million, 0.75% of the next $500 million of such assets, 0.70% of the next $500 million of such assets, 0.60% of the next $500 million of such assets, and 0.50% of the fund’s average daily net assets in excess of $2 billion. Dreyfus is the primary mutual fund business of The Bank of New York Mellon Corporation (BNY Mellon), a global financial services company focused on helping clients move and manage their financial assets, operating in 34 countries and serving more than 100 markets. BNY Mellon is a leading provider of financial services for institutions, corporations and high-net-worth individuals, providing asset and wealth management, asset servicing, issuer services, and treasury services through a worldwide client-focused team. BNY Mellon has more than $23 trillion in assets under custody and administration and $1.1 trillion in assets under management, and it services more than $13 trillion in outstanding debt. Additional information is available at www.bnymellon.com.

Effective on December 1, 2008 (Effective Date), Dreyfus was appointed to serve as the fund’s investment adviser. Prior to the Effective Date, The Boston Company Asset Management, LLC (TBCAM), an affiliate of Dreyfus, was the investment adviser for the fund. For the past fiscal year, the fund paid TBCAM an investment advisory fee at the annual rate of 0.60% of the fund’s average daily net assets. A discussion regarding the basis for the board’s approving the fund’s investment advisory agreement with Dreyfus is available in the fund’s annual report dated September 30, 2008.

William S. Patzer, Senior Vice President at TBCAM, has been the fund’s primary portfolio manager since August 2007. Mr. Patzer has been the lead portfolio manager of the Global Core Equity strategy at TBCAM since November 2006, and lead portfolio manager of TBCAM’s Emerging Markets Core Equity, International Core Equity and International Small Cap strategies since August 2007, and has been an employee of Dreyfus since August 2007. As a dual employee of Dreyfus and TBCAM, Mr. Patzer manages the fund as an employee of Dreyfus but uses TBCAM’s proprietary investment process. Mr. Patzer has also been a Research Analyst covering the health care sector since he joined TBCAM in November 2005. Prior to joining TBCAM, Mr. Patzer served as a Senior Analyst with Goldman Sachs Asset Management from September 2003 to February 2005.

The fund’s Statement of Additional Information (SAI) provides additional information about the portfolio manager’s compensation, other accounts managed by the portfolio manager, and the portfolio manager’s ownership of fund shares.

Distributor

Code of ethics

The Fund 7

FINANCIAL HIGHLIGHTS


		Year Ended September 30,
	2008	2007	2006	2005	2004
Net Asset Value, Beginning of Year	$46.03	$39.01	$34.34	$27.03	$21.62
From Investment Operations:
Net investment income (loss)*^(a)	0.49	0.78	0.71	0.50	0.31
Net realized and unrealized gain (loss) on investments	(10.82)	7.82	5.59	7.73	5.49
Total from operations	(10.33)	8.60	6.30	8.23	5.80
Less Distributions to Shareholders:
From net investment income	(0.44)	(0.60)	(0.40)	(0.39)	(0.39)
From net realized gains on investments	(17.98)	(0.98)	(1.23)	(0.53)	—
Total distributions to shareholders	(18.42)	(1.58)	(1.63)	(0.92)	(0.39)
Net Asset Value, End of Year	$17.28	$46.03	$39.01	$34.34	$27.03
Total Return	(35.03%)^(b)	22.37%^(b)	19.01%	31.06%	27.04%
Ratios/Supplemental data:
Expenses (to average daily net assets)*	0.87%	0.77%^(c)	0.88%^(c)	1.01%^(c)	1.12%^(c)
Net Investment Income (to average daily net assets)*	1.70%	1.78%	1.91%	1.59%	1.22%
Portfolio Turnover	98%	83%^(d)	51%^(d)	58%^(d)	80%^(d)
Net Assets, End of Year (000’s omitted)	$174,878	$1,257,378	$2,015,088	$287,065	$124,675

_____________________

* TBCAM, the fund’s former investment adviser, voluntarily agreed not to impose a portion of its investment advisory fee and/or reimbursed the

fund for all or a portion of its operating expenses. If this voluntary action had not been taken, the investment income per share and the ratios

without waivers and reimbursements would have been:


Net investment income per share^(a)	$0.44	$0.78	n/a	n/a	n/a
Ratios (to average daily net assets):
Expenses^(c)	1.07%	0.78%	n/a	n/a	n/a
Net investment income	1.51%	1.77%	n/a	n/a	n/a

(a)Calculated based on average shares outstanding.

(b)Total return would have been lower in the absence of expense waivers.

(c) For the period October 1, 2006 to September 19, 2007, and for the fiscal years ended September 30, 2004-2006, the ratio includes the fund’s share of The Boston

Company International Core Equity Portfolio’s (the Portfolio) allocated expenses.

(d)On September 19, 2007, the fund, which had owned 100% of the Portfolio on such date, withdrew entirely from the Portfolio and received the Portfolio’s securities

and cash in exchange for its interests in the Portfolio. Effective September 20, 2007, the fund began investing directly in the securities in which the Portfolio had

invested. Portfolio turnover represents investment activity of both the fund and the Portfolio for the year.The amounts shown for 2004-2006 are the ratios for the

Portfolio.

Your Investment

ACCOUNT POLICIES

Shares of the fund are available only to limited types of investors, and may be purchased by:

bank trust departments, trust companies and insurance companies that have entered into agreements with the fund’s distributor to offer fund shares to their clients
institutional investors acting in a fiduciary, advisory, agency, custodial or similar capacity for qualified or non-qualified employee benefit plans, including pension, profit-sharing and other deferred compensation plans, whether established by corporations, partnerships, non-profit entities, trade or labor unions, or state and local governments, and IRAs set up under Simplified Employee Pension Plans that have entered into agreements with the fund’s distributor to offer fund shares to such plans
law firms or attorneys acting as trustees or executors/administrators
foundations and endowments that make an initial investment in the fund of at least $1 million
sponsors of college savings plans that qualify for tax-exempt treatment under Section 529 of the Internal Revenue Code, that maintain an omnibus account with the fund and do not require shareholder tax reporting or 529 account support responsibilities from the fund’s distributor
advisory fee-based accounts offered through financial intermediaries who, depending on the structure of the selected advisory platform, make fund shares available

Your order will be priced at the next NAV calculated after your order is received in proper form by the fund’s transfer agent or other authorized entity.

Concept to understand

Net asset value (NAV): a mutual fund’s share price on a given day. A fund’s NAV is calculated by dividing the value of its net assets by the number of its existing shares outstanding.

Your Investment 9

ACCOUNT POLICIES (continued)

Investments in foreign securities and certain thinly traded securities may provide short-term traders arbitrage opportunities with respect to the fund’s shares. For example, arbitrage opportunities may exist when trading in a portfolio security or securities is halted and does not resume, or the market on which such securities are traded closes before the fund calculates its NAV. If short-term investors in the fund were able to take advantage of these arbitrage opportunities, they could dilute the NAV of fund shares held by long-term investors. Portfolio valuation policies can serve to reduce arbitrage opportunities available to short-term traders, but there is no assurance that such valuation policies will prevent dilution of the fund’s NAV by short-term traders.While the fund has a policy regarding frequent trading, it too may not be completely effective to prevent short-term NAV arbitrage trading, particularly in regard to omnibus accounts. Please see “Your Investment — Account Policies —General Policies” for further information about the fund’s frequent trading policy.


Minimum investments^†
	Initial	Additional
Regular accounts	$1,000	$100

<R></R>

All investments must be in U.S. dollars. Third-party checks, cash, travelers’ checks or money orders will not be accepted. You may be charged a fee for any check that does not clear.

^†The minimum initial investment for foundations and endowments is

$1 million.

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Selling shares

Before selling shares recently purchased by check, please note that:

if you send a written request to sell such shares, the fund may delay sending the proceeds for up to eight business days following the purchase of those shares
the fund will not process wire or telephone redemption requests for up to eight business days following the purchase of those shares

Redemption fee

Frequent trading can disrupt a fund’s investment program and create additional costs for long-term shareholders. For these reasons, a 2% fee will be assessed on redemptions (including exchanges) of fund shares held for less than 60 days.The redemption fee is paid directly to the fund and is designed to offset brokerage commissions, market impact, and other costs associated with frequent trading.

Subject to the exceptions described below, shares purchased and held for less than 60 days will be subject to the fund’s redemption fee, whether held directly in your name or indirectly through an intermediary, such as a broker, bank, investment adviser, recordkeeper for retirement plan participants, or any other third party. If you hold your shares through an intermediary’s omnibus account, the intermediary is responsible for imposing the fee and remitting the fee to the fund.

Dreyfus will use the “first-in, first-out” method to determine the holding period for the shares sold. Under this method, shares held the longest will be redeemed or exchanged first. The holding period commences on the day after your purchase order is effective.

The fund will not assess a redemption fee on fund shares (1) redeemed through automatic withdrawal plans or automatic exchange plans; (2) redeemed through certain comprehensive fee programs, such as wrap fee accounts and automated rebalancing or asset allocation programs offered by financial intermediaries (including those sponsored by Dreyfus or its affiliates); (3) acquired by the reinvestment of fund dividends or capital gain distributions; (4) redeemed by the fund (e.g., for failure to meet account minimums or to cover various fees); (5) purchased or redeemed by rollover, transfers and changes of account registration, provided that the investment remains in the fund; (6) purchased by other mutual funds, if approved by Dreyfus; (7) held in accounts in which there are legal or contractual restrictions on the imposition of a redemption fee as determined by the fund in its sole discretion; (8) redeemed as a result of death, disability or a Qualified Domestic Relations Order; (9) redeemed from Coverdell Education Savings Accounts to pay qualified education expenses; (10) redeemed from 529 Plans; and (11) converted from one share class to another in the fund.

In addition, the fund will not impose redemption fees on certain types of retirement plan transactions processed through a participant recordkeeping system supported by Dreyfus or through third party recordkeepers. These transactions include: (1) redemptions of shares purchased with new contributions to the plan, such as payroll contributions, excess contributions, and loan repayments; (2) shares redeemed for withdrawals and distributions, such as minimum required distributions, systematic withdrawal programs, and lump sum distributions; (3) redemptions by plan participants of investments made on their behalf into Qualified Default Investment Alternatives (“QDIAs”); (4) shares redeemed by participation in automated account rebalancing programs or other systematic participant investment advice programs approved by the

Your Investment 11

ACCOUNT POLICIES (continued)

plan sponsor; (5) shares purchased or redeemed as a result of plan sponsor decisions, such as changes in investment options and plan termination or merger; (6) shares redeemed for loans, or following a hardship specified in the retirement plan documents; and (7) forfeitures or redemptions in connection with a participant’s termination of employment.The fund may waive redemption fees for certain retirement plans that have implemented automated processes or other procedures to prevent frequent trading. Such waivers require the written approval of the fund.

The fund reserves the right to withdraw waivers in its sole discretion without notice if the fund determines that an account is engaging in frequent trading or other activities detrimental to the fund.

If you hold your shares through a financial intermediary that does not process your share transactions in an omnibus account, the intermediary is responsible for providing Dreyfus with the information necessary to enable you to receive any redemption fee waivers to which you may be entitled.

While the fund seeks to apply its redemption fee policy to all accounts, the fund cannot assure that all intermediaries will properly assess the fees in omnibus accounts. In addition, due to operational limitations or restrictions, retirement plans and intermediaries that maintain omnibus accounts with the fund may calculate redemption fees differently than the fund. If you are investing in fund shares through an intermediary (or in the case of a retirement plan, your plan sponsor), please contact the intermediary for more information on any differences in how the redemption fee may be applied to your investment in the fund.


Limitations on selling shares by phone

Proceeds	Minimum	Maximum
sent by	phone	phone

Check	no minimum	$250,000 per day

Wire	$1,000	$500,000 for joint
		accounts every 30 days/
		$20,000 per day

Written sell orders

Some circumstances require written sell orders along with signature guarantees. These include:

amounts of $10,000 or more on accounts whose address has been changed within the last 30 days
requests to send the proceeds to a different payee or address

Written sell orders of $100,000 or more must also be signature guaranteed.

General policies

Unless you decline teleservice privileges on your application, the fund’s transfer agent is authorized to act on telephone instructions from any person representing himself or herself to be you and reasonably believed by the transfer agent to be genuine.You may be responsible for any fraudulent telephone order as long as the fund’s transfer agent takes reasonable measures to confirm that instructions are genuine.

The fund reserves the right to:

change or discontinue its exchange privilege, or temporarily suspend the privilege during unusual market conditions
change its minimum or maximum investment amounts
delay sending out redemption proceeds for up to seven days (generally applies only during unusual market conditions or in cases of very large redemptions or excessive trading)
“redeem in kind,” or make payments in securities rather than cash, if the amount redeemed is large enough to affect fund operations (for example, if it exceeds 1% of the fund’s assets)
refuse any purchase or exchange request, including those from any individual or group who, in Dreyfus’ view, is likely to engage in frequent trading

More than four roundtrips within a rolling 12-month period generally is considered to be frequent trading. A roundtrip consists of an investment that is substantially liquidated within 60 days. Based on the facts and circumstances of the trades, the fund may also view as frequent trading a pattern of investments that are partially liquidated within 60 days.

Your Investment 13

ACCOUNT POLICIES (continued)

Third-party investments

Although the fund’s redemption fee and frequent trading and fair valuation policies and procedures are designed to discourage market timing and excessive trading, none of these tools alone, nor all of them together, completely eliminates the potential for frequent trading.

Small account policy

If your account falls below $500, the fund may ask you to increase your balance. If it is still below $500 after 30 days, the fund may close your account and send you the proceeds.

DISTRIBUTIONS AND TAXES

The tax status of your distributions will be detailed in your annual tax statement from the fund. Because everyone’s tax situation is unique, please consult your tax advisor before investing.

Your Investment 15

EXCHANGE PRIVILEGE

You can exchange shares worth $500 or more (no minimum for retirement accounts) of the fund for Class I shares of other Dreyfus funds or for shares of certain other Dreyfus funds. You can request your exchange in writing or by phone. Be sure to read the current prospectus for any fund into which you are exchanging before investing. Any new account established through an exchange will have the same privileges as your original account (as long as they are available). Although there is currently no fee for exchanges, the fund may deduct a 2% redemption fee if you are selling or exchanging shares you have owned for less than 60 days, and you also may be charged a sales load when exchanging into any fund that has one.

For information and other assistance, call toll free in the U.S.

1-800-645-6561.

Outside the U.S. 516-794-5452.

Make checks payable to: The Dreyfus Family of Funds

Concept to understand

Wire transfer: for transferring money from one financial institution to another. Wiring is the fastest way to move money, although your bank may charge a fee to send or receive wire transfers. Wire redemptions from the fund are subject to a $1,000 minimum.

Your Investment 17

For More Information

Dreyfus/The Boston Company

International Core Equity Fund

A series of Dreyfus Investment Funds

SEC file number: 811-4813

More information on this fund is available free upon request, including the following:

Annual/Semiannual Report

Statement of Additional Information (SAI)

Portfolio Holdings

A complete description of the fund’s policies and procedures with respect to the disclosure of the fund’s portfolio securities is available in the fund’s SAI.

To obtain information:

By telephone

Call your financial representative or 1-800-645-6561

By mail Write to:

The Dreyfus Family of Funds

144 Glenn Curtiss Boulevard

Uniondale, NY 11556-0144

By E-mail Send your request to info@dreyfus.com

On the Internet Text-only versions of certain fund documents can be viewed online or downloaded from:

SEC http://www.sec.gov

Dreyfus http://www.dreyfus.com

Dreyfus/The Boston Company

International Small Cap Fund

Seeks long-term growth of capital

by investing in equity securities of

small-cap foreign companies

PROSPECTUS February 1, 2009

<R>As revised, April 15, 2009</R>


Contents


The Fund
Goal/Approach	1
Main Risks	2
Past Performance	4
Expenses	5
Management	6
Financial Highlights	8

Your Investment
Account Policies	9
Distributions and Taxes	15
Exchange Privilege	16
Account Instructions	17

For More Information
See back cover.

The Fund

Dreyfus/The Boston Company

International Small Cap Fund

Ticker Symbol SDISX

GOAL/APPROACH

The fund seeks long-term growth of capital. This objective may be changed without shareholder approval. To pursue its goal, the fund normally invests at least 80% of its assets in equity securities of companies that are located in foreign countries represented in the S&P Developed Ex-U.S. Small Cap Index (EMI Ex-U.S.) Index.The fund’s equity investments may include common stocks, preferred stocks, convertible securities and warrants, including those purchased in initial public offerings (IPOs) or shortly thereafter. The fund also may invest up to 20% of its assets in high grade fixed-income securities (i.e., rated A or better or the unrated equivalent) of any maturity or duration, and may invest up to 5% of its assets in fixed-income securities in the lowest long-term investment grade category (i.e., rated Baa-/BBB- or the unrated equivalent).

The fund normally invests at least 80% of its assets in those companies which, at the time of purchase, have total market capitalizations that fall in the range of the capitalizations of the companies that comprise the EMI Ex-U.S. Index. The EMI Ex-U.S. Index is made up of those companies representing the lowest 20% of each country’s total available market capitalization. The fund intends to invest in a broad range of (and in any case at least five different) countries.The fund is not required to invest in every country represented in, or to match the country weightings of, the EMI Ex-U.S. Index. The fund may invest up to 25% of its assets in securities of issuers located in emerging market countries, but no more than 5% of its assets may be invested in issuers located in any one emerging market country.

The fund invests in stocks that appear to be undervalued (as measured by their price/earnings ratios) and that may have value and/or growth characteristics.The portfolio managers employ a bottom-up investment approach which emphasizes individual stock selection.

Stock selection—The portfolio managers use proprietary quantitative models and traditional qualitative analysis to identify attractive stocks with low relative price multiples and positive trends in earnings forecasts.
Country allocations—The portfolio managers seek generally to allocate country weights in accordance with the EMI Ex-U.S. Index, but deviations from the EMI Ex-U.S. weightings may occur.
Sector and industry allocations—The portfolio managers use the sector and industry allocations of the EMI Ex-U.S. Index as a guide, but allocations may differ from those of the EMI Ex-U.S. Index.

The fund’s stock selection process is designed to produce a diversified portfolio that, relative to the EMI Ex-U.S. Index, frequently has a below-average price-earnings ratio and an above-average earnings growth trend.

Concepts to understand

EMI Ex-U.S. Index: represents, on a country-by-country basis, the small capitalization component of the S&P Global BMI^SM, which is a comprehensive float-weighted index of companies in 51 countries (excluding the United States) with market capitalizations of at least $100 million.

The Fund 1

MAIN RISKS

Foreign investment risk. The fund’s performance will be influenced by political, social and economic factors affecting investments in foreign companies. Special risks associated with investments in foreign companies include exposure to currency fluctuations, less liquidity, less developed or less efficient trading markets, lack of comprehensive company information, political and economic instability and differing auditing and legal standards.
Foreign currency risk. Investments in foreign currencies are subject to the risk that those currencies will decline in value relative to the U.S. dollar, or, in the case of hedged positions, that the U.S. dollar will decline relative to the currency being hedged. Currency rates in foreign countries may fluctuate significantly over short periods of time.A decline in the value of foreign currencies relative to the U.S. dollar will reduce the value of securities held by the fund and denominated in those currencies. Foreign currencies are also subject to risks caused by inflation, interest rates, budget deficits and low savings rates, political factors and government controls.
Emerging market risk. Emerging markets tend to be more volatile than the markets of more mature economies, and generally have less diverse and less mature economic structures and less stable political systems than those of developed countries. The securities of companies located in emerging markets are often subject to rapid and large changes in price.
Market risk. The market value of a security may decline due to general market conditions that are not specifically related to a particular company, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates or adverse investor sentiment generally. A security’s market value also may decline because of factors that affect a particular industry or industries, such as labor shortages or increased production costs and competitive conditions within an industry.
Issuer risk. The value of a security may decline for a number of reasons which directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer’s products or services.
Small company risk. Small companies carry additional risks because their operating histories tend to be more limited, their earnings and revenues tend to be less predictable (and some companies may be experiencing significant losses), and their share prices more volatile than those of larger, more established companies.The shares of smaller companies tend to trade less frequently than those of larger, more established companies, which can adversely affect the pricing of smaller companies’ securities and the fund’s ability to sell them when the portfolio managers deem it appropriate. These companies may have limited product lines, markets and/or financial resources, or may depend on a limited management group. Some of the fund’s investments will rise and fall based on investor perception rather than economic factors. Other investments, including special situations, are made in anticipation of future products and services or events whose delay or cancellation could cause the stock price to drop.
Value/Growth stock risk. By investing in a mix of value and growth companies, the fund assumes the risks of both. Because different types of stocks tend to shift in and out of favor depending on market and economic conditions, the fund’s performance may sometimes be lower or higher than that of other types of funds.Value stocks involve the risk that they may never reach what the portfolio managers believe is their full market value, either because the market fails to recognize the stock’s intrinsic worth or the portfolio managers misgauged that worth. They also may decline in price, even though in theory they are already undervalued. Investors often expect growth companies to increase their earnings at a certain rate. If these expectations are not met, investors can punish the stocks inordinately, even if earnings do increase. In addition, growth stocks typically lack the dividend yield that can cushion stock prices in market downturns.

Market sector risk.The fund may significantly overweight or underweight certain companies, industries or market sectors, which may cause the fund’s performance to be more or less sensitive to developments affecting those companies, industries or sectors.
Derivatives risk. The fund may use derivative instruments, such as options, futures and options on futures (including those relating to securities, indexes, foreign currencies and interest rates), and forward contracts. A small investment in derivatives could have a potentially large impact on the fund’s performance. The use of derivatives involves risks different from, or possibly greater than, the risks associated with investing directly in the underlying assets. Derivatives can be highly volatile, illiquid and difficult to value, and there is the risk that changes in the value of a derivative held by the fund will not correlate with the underlying instruments or the fund’s other investments. Derivative instruments also involve the risk that a loss may be sustained as a result of the failure of the counterparty to the derivative instruments to make required payments or otherwise comply with the derivative instruments’ terms.
Leveraging risk. The use of leverage, such as lending portfolio securities, entering into futures contracts or forward currency contracts, entering into reverse repurchase agreements and engaging in forward commitment transactions, may magnify the fund’s gains or losses.
IPO risk. The fund may purchase securities of companies in IPOs.The prices of securities purchased in IPOs can be very volatile.The effect of IPOs on the fund’s performance depends on a variety of factors, including the number of IPOs the fund invests in relative to the size of the fund and whether and to what extent a security purchased in an IPO appreciates or depreciates in value. As a fund’s asset base increases, IPOs often have a diminished effect on such fund’s performance.

Other potential risks

The fund may engage in short-term trading, which could produce higher transaction costs and taxable distributions and lower the fund’s after-tax performance.

The Fund 3

PAST PERFORMANCE

The bar chart and table shown illustrate the risks of investing in the fund. The bar chart shows the changes in the fund’s performance from year to year. The table compares the fund’s average annual total returns to those of the EMI Ex-U.S. Index, a broad measure of the performance of the stocks of small-cap companies in approximately 51 countries, excluding the United States. For periods prior to the fund’s inception on January 31, 2000, the performance figures for the fund in the bar chart and the table represent the performance of the fund’s predecessor, SIMCO International Small Cap Fund, L.P., which began operations on January 2, 1996.The predecessor fund was not registered as a mutual fund and therefore was not subject to certain investment restrictions that are imposed upon mutual funds. If the predecessor fund had been registered as a mutual fund, the predecessor fund’s performance may have been adversely affected. The performance of the predecessor fund was calculated according to the standardized Securities and Exchange Commission methods except that monthly rather than daily fund values were used.All returns assume reinvestment of dividends and distributions. Of course, past performance (before and after taxes) is no guarantee of future results.

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Year-by-year total returns as of 12/31 each year (%)

Fund shares


Best Quarter:	Q2 ‘03	+19.86%
Worst Quarter:	Q4 ‘08	-25.46%


Average annual total returns as of 12/31/08

	1 Year	5 Years	10 Years

Fund
returns before taxes	-50.90%	2.19%	8.68%

Fund
returns after taxes
on distributions	-50.83%	-1.38%	6.58%

Fund
returns after taxes
on distributions and
sale of fund shares	-32.85%	4.86%	9.27%

EMI Ex-U.S. Index
reflects no deduction for
fees, expenses or taxes	-47.67%	2.70%	4.28%

EXPENSES


Fee table

Shareholder transaction fees
(fees paid from your account)
Maximum redemption fee	2.00
% of transaction amount
charged only when selling shares you
have owned for less than 60 days

Annual fund operating expenses
(expenses paid from fund assets)
% of average daily net assets
Management fees	1.00
Other expenses	.53
Total	1.53


Expense example
1 Year	3 Years	5 Years	10 Years
$156	$483	$834	$1,824

Concepts to understand

Management fee: the fee paid to Dreyfus for managing the fund’s portfolio and assisting in all aspects of the fund’s operations.

For the fiscal year ended September 30, 2008, a portion of the fund’s expenses were waived or reimbursed, reducing the fund’s total annual operating expenses from 1.53% to 1.28%. This waiver is voluntary and may be terminated at any time.

The Fund 5

MANAGEMENT

Investment adviser

Effective on December 1, 2008 (Effective Date), Dreyfus was appointed to serve as the fund’s investment adviser. Prior to the Effective Date, The Boston Company Asset Management, LLC (TBCAM), an affiliate of Dreyfus, was the investment adviser for the fund. For the past fiscal year, the fund paid TBCAM an investment advisory fee at the annual rate of 0.75% of the fund’s average daily net assets. A discussion regarding the basis for the board’s approving the fund’s investment advisory agreement with Dreyfus is available in the fund’s annual report dated September 30, 2008.

William S. Patzer and Mark A. Bogar are the fund’s primary portfolio managers, positions they have held since August 2007 and May 2008, respectively. Mr. Patzer has been the lead portfolio manager of the Global Core Equity strategy at TBCAM since November 2006, and lead portfolio manager of TBCAM’s Emerging Markets Core Equity, International Core Equity and International Small Cap strategies since August 2007, and has been an employee of Dreyfus since August 2007. Mr. Patzer has also been a Research Analyst covering the health care sector since he joined TBCAM in November 2005. Prior to joining TBCAM, Mr. Patzer served as a Senior Analyst with Goldman Sachs Asset Management from September 2003 to February 2005. Mr. Bogar is a portfolio manager and Senior Equity Research Analyst of TBCAM’s International Core and Growth Strategies since August 2007. His research responsibilities include the consumer staples and consumer discretionary sectors. Prior to August 2007, Mr. Bogar was a portfolio manager at Putnam Investments for their Global Core Equity strategy. Mr. Bogar has been an employee of Dreyfus since December 2008.As dual employees of Dreyfus and TBCAM, Mr. Patzer and Mr. Bogar manage the fund as employees of Dreyfus but use TBCAM’s proprietary investment process.

Distributor

Code of ethics

The Fund 7

FINANCIAL HIGHLIGHTS

These financial highlights have been audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm, whose report on the fund’s financial statements contained in the financial highlights, is included in the annual report, which is available upon request.


		Year Ended September 30,
	2008^(a)	2007^(a)	2006^(a)	2005^(a)	2004^(a)

Net Asset Value, Beginning of Year	$267.30	$240.30	$208.40	$159.30	$120.50
From Investment Operations:
Net investment income*^(b)	0.52	1.30	1.80	2.30	1.40
Net realized and unrealized gain (loss) on investments	(29.50)	54.80	45.20	58.60	38.60
Total from operations	(28.98)	56.10	47.00	60.90	40.00
Less Distributions to Shareholders:
From net investment income	(0.59)	(1.90)	(1.90)	(1.70)	(1.20)
From net realized gains on investments	(229.62)	(27.20)	(13.20)	(10.10)	—
Total distributions to shareholders	(230.21)	(29.10)	(15.10)	(11.80)	(1.20)
Net Asset Value, End of Year	$8.11	$267.30	$240.30	$208.40	$159.30
Total Return	(39.92%)^(c)24.50%^(c)		23.72%	40.20%	33.35%
Ratios/Supplemental Data:
Expenses (to average daily net assets)*	1.28%	1.10%^(d)	1.11%^(d)	1.16%^(d)	1.27%^(d)
Net Investment Income (to average daily net assets)*	0.69%	0.68%	0.79%	1.26%	0.99%
Portfolio Turnover	136%	88%^(e)	65%^(e)	50%^(e)	72%^(e)
Net Assets, End of Year (000’s omitted)	$57,440	$564,691	$758,691	$524,910	$212,032

________________

* For the periods indicated,TBCAM, the fund’s former investment adviser, voluntarily agreed not to impose a portion of its investment advisory

fee and/or reimbursed the fund for all or a portion of its operating expenses. If this voluntary action had not been taken, the investment

income per share and the ratios without waivers and reimbursements would have been:


Net investment income per share^(b)	$0.34	$1.30	n/a	n/a	n/a
Ratios (to average daily net assets):
Expenses	1.53%	1.12%^(d)	n/a	n/a	n/a
Net investment income	0.45%	0.66%	n/a	n/a	n/a


(a)	Amounts were adjusted to reflect a 1:10 reverse share split January 24, 2008.
(b)	Calculated based on average shares outstanding.
(c)	Total return would have been lower in the absence of expense waivers.
(d)	For the period October 1, 2006 to September 19, 2007 and for the fiscal years ended September 30, 2004-2006, the ratios include the fund’s share of the TBC
	International Small Cap Portfolio’s (Portfolio) allocated expenses.
(e)	On September 19, 2007, the fund, which had owned approximately 100% of the Portfolio on such date, withdrew entirely from the Portfolio and received the
	Portfolio’s securities and cash in exchange for its interest in the Portfolio. Effective September 20, 2007, the fund began investing directly in the securities in which
	the Portfolio had invested. Portfolio turnover represents investment activity of both the fund and the Portfolio for the year.The amounts shown for 2004-2006 are
	the ratios for the Portfolio.

Your Investment

ACCOUNT POLICIES

Shares of the fund are available only to limited types of investors, and may be purchased by:

bank trust departments, trust companies and insurance companies that have entered into agreements with the fund’s distributor to offer fund shares to their clients
institutional investors acting in a fiduciary, advisory, agency, custodial or similar capacity for qualified or non-qualified employee benefit plans, including pension, profit-sharing and other deferred compensation plans, whether established by corporations, partnerships, non-profit entities, trade or labor unions, or state and local governments, and IRAs set up under Simplified Employee Pension Plans that have entered into agreements with the fund’s distributor to offer fund shares to such plans
law firms or attorneys acting as trustees or executors/administrators
foundations and endowments that make an initial investment in the fund of at least $1 million
sponsors of college savings plans that qualify for tax-exempt treatment under Section 529 of the Internal Revenue Code, that maintain an omnibus account with the fund and do not require shareholder tax reporting or 529 account support responsibilities from the fund’s distributor
advisory fee-based accounts offered through financial intermediaries who, depending on the structure of the selected advisory platform, make fund shares available

You pay no sales charges to invest in the fund. Your price for fund shares is the fund’s net asset value per share (NAV), which is generally calculated as of the close of trading on the New York Stock Exchange (usually 4:00 p.m. Eastern time) on days the exchange is open for regular business.

Your order will be priced at the next NAV calculated after your order is received in proper form by the fund’s transfer agent or other authorized entity.

When calculating its NAV, the fund’s investments are valued on the basis of market quotations or official closing prices. If market quotations or official closing prices are not readily available, or are determined not to reflect accurately fair value (such as when the value of a security has been materially affected by events occurring after the close of the exchange or market on which the security is principally traded (for example, a foreign exchange or market), but before the fund calculates its NAV), the fund may value those investments at fair value as determined in accordance with procedures approved by the fund’s board. Fair value of investments may be determined by the fund’s board, its pricing committee or its valuation committee in good faith using such information as it deems appropriate under the circumstances. Fair value of foreign equity securities may be determined with the assistance of a pricing service using correlations between the movement of prices of foreign securities and indexes of domestic securities and other appropriate indicators, such as closing market prices of relevant ADRs and futures contracts. Using fair value to price securities may result in a value that is different from a security’s most recent closing price and from the prices used by other mutual funds to calculate their net asset values. Forward currency contracts will be valued at the current cost of offsetting the contract. Foreign securities may trade on days when the fund does not calculate its NAV and thus may affect the fund’s NAV on days when investors have no access to the fund.

Your Investment 9

ACCOUNT POLICIES (continued)

Concept to understand

Net asset value (NAV): a mutual fund’s share price on a given day. A fund’s NAV is calculated by dividing the value of its net assets by the number of its existing shares outstanding.


Minimum investments^†
	Initial	Additional
Regular accounts	$1,000	$100

<R></R>

All investments must be in U.S. dollars. Third-party checks, cash, travelers’ checks or money orders will not be accepted. You may be charged a fee for any check that does not clear.

^†The minimum initial investment for foundations and endowments is

$1 million.

<R></R>

Selling shares

Before selling shares recently purchased by check, please note that:

if you send a written request to sell such shares, the fund may delay sending the proceeds for up to eight business days following the purchase of those shares
the fund will not process wire or telephone redemption requests for up to eight business days following the purchase of those shares

Redemption fee

Your Investment 11

ACCOUNT POLICIES (continued)

result of plan sponsor decisions, such as changes in investment options and plan termination or merger; (6) shares redeemed for loans, or following a hardship specified in the retirement plan documents; and (7) forfeitures or redemptions in connection with a participant’s termination of employment.The fund may waive redemption fees for certain retirement plans that have implemented automated processes or other procedures to prevent frequent trading. Such waivers require the written approval of the fund.


Limitations on selling shares by phone

Proceeds	Minimum	Maximum
sent by	phone	phone

Check	no minimum	$250,000 per day

Wire	$1,000	$500,000 for joint
		accounts every 30 days/
		$20,000 per day

Written sell orders

Some circumstances require written sell orders along with signature guarantees. These include:

amounts of $10,000 or more on accounts whose address has been changed within the last 30 days
requests to send the proceeds to a different payee or address

Written sell orders of $100,000 or more must also be signature guaranteed.

General policies

The fund reserves the right to:

change or discontinue its exchange privilege, or temporarily suspend the privilege during unusual market conditions
change its minimum or maximum investment amounts
delay sending out redemption proceeds for up to seven days (generally applies only during unusual market conditions or in cases of very large redemptions or excessive trading)
“redeem in kind,” or make payments in securities rather than cash, if the amount redeemed is large enough to affect fund operations (for example, if it exceeds 1% of the fund’s assets)
refuse any purchase or exchange request, including those from any individual or group who, in Dreyfus’ view, is likely to engage in frequent trading

Your Investment 13

ACCOUNT POLICIES (continued)

Third-party investments

Small account policy

If your account falls below $500, the fund may ask you to increase your balance. If it is still below $500 after 30 days, the fund may close your account and send you the proceeds.

DISTRIBUTIONS AND TAXES

The tax status of your distributions will be detailed in your annual tax statement from the fund. Because everyone’s tax situation is unique, please consult your tax advisor before investing.

Your Investment 15

EXCHANGE PRIVILEGE

You can exchange shares worth $500 or more (no minimum for retirement accounts) of the fund for Class I shares of other Dreyfus funds or for shares of certain other Dreyfus funds. You can request your exchange in writing or by phone. Be sure to read the current prospectus for any fund into which you are exchanging before investing. Any new account established through an exchange will have the same privileges as your original account (as long as they are available). Although there is currently no fee for exchanges, the fund may deduct a 2% redemption fee if you are selling or exchanging shares you have owned for less than 60 days, and you also may be charged a sales load when exchanging into any fund that has one.

For information and other assistance, call toll free
in the U.S. 1-800-645-6561.

Outside the U.S. 516-794-5452.

Make checks payable to: The Dreyfus Family of Funds.

Your Investment 17

For More Information

Dreyfus/The Boston Company

International Small Cap Fund

A series of Dreyfus Investment Funds

SEC file number: 811-4813

More information on this fund is available free upon request, including the following:

Annual/Semiannual Report

Statement of Additional Information (SAI)

Portfolio Holdings

A complete description of the fund’s policies and procedures with respect to the disclosure of the fund’s portfolio securities is available in the fund’s SAI.

To obtain information:

By telephone

Call your financial representative or 1-800-645-6561

By mail Write to:

The Dreyfus Family of Funds

144 Glenn Curtiss Boulevard

Uniondale, NY 11556-0144

By E-mail Send your request to info@dreyfus.com

On the Internet Text-only versions of certain fund documents can be viewed online or downloaded from:

SEC http://www.sec.gov

Dreyfus http://www.dreyfus.com

Dreyfus/The Boston Company

Small Cap Value Fund II

Seeks long-term growth of capital

by investing in equity securities of

small cap U.S. companies

PROSPECTUS February 1, 2009

<R>As revised, April 15, 2009</R>


Contents


The Fund
Goal/Approach	1
Main Risks	2
Past Performance	4
Expenses	5
Management	6
Financial Highlights	8

Your Investment
Account Policies	9
Distributions and Taxes	14
Exchange Privilege	15
Account Instructions	16

For More Information
See back cover.

The Fund

Dreyfus/The Boston Company Small Cap Value Fund II

Ticker Symbol SBSVX

GOAL/APPROACH

The fund seeks long-term growth of capital. This objective may be changed without shareholder approval.To pursue its goal, the fund normally invests at least 80% of its assets in equity securities of small-cap U.S. companies. The fund currently considers small-cap companies to be those with total market capitalizations, at the time of purchase, that are within the range of market capitalizations of companies included in the Russell 2500^®Index.The fund normally seeks to maintain for its equity investments an average weighted market capitalization, as measured on a monthly basis, that approximates that of the Russell 2500 Index,which,as of December 31,2008, was $1.18 billion.Although the fund normally invests in U.S.-based companies, it may invest up to 15% of its assets in foreign companies, including up to 10% of its assets in issuers located in emerging market countries, and up to 3% of its assets in issuers of any one specific emerging market country. The fund’s equity investments may include common stocks, preferred stocks, convertible securities and warrants, including those purchased in initial public offerings (IPOs) or shortly thereafter.The fund also may invest up to 20% of its assets in high grade fixed-income securities (i.e.,rated A or better or the unrated equivalent) with remaining maturities of three years or less, and may invest up to 5% of its assets in fixed-income securities in the lowest long-term investment grade category (i.e., rated Baa-/BBB- or the unrated equivalent).

The portfolio managers use fundamental research and qualitative analysis to select stocks among the portfolio candidates. The portfolio managers look for companies with strong competitive positions, high quality management, and financial strength. A company’s competitive position is assessed given its market share, available financial resources to finance growth and the proven ability to develop new products and services. A company’s financial strength is evaluated based on various metrics, including balance sheet quality (constituency of assets given the amount of leverage), profitability and margin strength, free cash flow and estimated earnings over the next two years.

Valuation: to identify small cap companies that are considered to be attractively priced relative to their earnings potential;
Fundamentals: to verify the strength of the underlying business position; and
Catalyst: to identify a specific event that has the potential to cause the stocks to appreciate in value.

Concepts to understand

Value companies: companies that appear underpriced according to certain financial measurements of their intrinsic worth or business prospects (such as price-to-earnings, price-to-sales or price-to-cash-flow ratios). Because a stock can remain undervalued for years, certain value investors often look for factors that could trigger a rise in price.

Russell 2500 Value Index: an unmanaged index, which is the fund’s benchmark index, that measures the performance of those Russell 2500 companies (the 2,500 smallest companies in the Russell 3000^®Index (which is comprised of the 3,000 largest U.S. companies based on total market capitalization)) with lower price-to-book ratios and lower forecasted growth values. As of December 31, 2008, the market capitalizations of the companies included in the Russell 2500 Index ranged from $7.0 million to $6.85 billion.

The Fund 1

MAIN RISKS

Market risk. The market value of a security may decline due to general market conditions that are not specifically related to a particular company, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates or adverse investor sentiment generally. A security’s market value also may decline because of factors that affect a particular industry or industries, such as labor shortages or increased production costs and competitive conditions within an industry.
Issuer risk. The value of a security may decline for a number of reasons which directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer’s products or services.
Small company risk. Small companies carry additional risks because their operating histories tend to be more limited, their earnings and revenues less predictable (and some companies may be experiencing significant losses), and their share prices more volatile than those of larger, more established companies.The shares of smaller companies tend to trade less frequently than those of larger, more established companies, which can adversely affect the pricing of smaller companies’ securities and the fund’s ability to sell them when the portfolio managers deem it appropriate.These companies may have limited product lines, markets and/or financial resources, or may depend on a limited management group. Some of the fund’s investments will rise and fall based on investor perception rather than economic factors. Other investments, including special situations, are made in anticipation of future products and services or events whose delay or cancellation could cause the stock price to drop.
Value stock risk. Value stocks involve the risk that they may never reach what the portfolio managers believe is their full market value, either because the market fails to recognize the stock’s intrinsic worth or the portfolio managers mis-gauged that worth. They also may decline in price, even though in theory they are already undervalued. Because different types of stocks tend to shift in and out of favor depending on market and economic conditions, the fund’s performance may sometimes be lower or higher than that of other types of funds (such as those emphasizing growth stocks).
Market sector risk.The fund may significantly overweight or underweight certain companies, industries or market sectors, which may cause the fund’s performance to be more or less sensitive to developments affecting those companies, industries or sectors.
Foreign investment risk. To the extent the fund invests in foreign securities, its performance will be influenced by political, social and economic factors affecting investments in foreign companies. Special risks associated with investments in foreign companies include exposure to currency fluctuations, less liquidity, less developed or less efficient trading markets, lack of comprehensive company information, political and economic instability and differing auditing and legal standards.The securities of issuers located in emerging markets can be more volatile and less liquid than those of issuers in more mature economies.
Foreign currency risk. Investments in foreign currencies are subject to the risk that those currencies will decline in value relative to the U.S. dollar, or, in the case of hedged positions, that the U.S. dollar will decline relative to the currency being hedged. Currency rates in foreign countries may fluctuate significantly over short periods of time.A decline in the value of foreign currencies relative to the U.S. dollar will reduce the value of securities held by the fund and denominated in those currencies. Foreign currencies are also subject to risks caused by inflation, interest rates, budget deficits and low savings rates, political factors and government controls.

Emerging market risk. Emerging markets tend to be more volatile than the markets of more mature economies, and generally have less diverse and less mature economic structures and less stable political systems than those of developed countries. The securities of companies located in emerging markets are often subject to rapid and large changes in price.
Derivatives risk. The fund may use derivative instruments, such as options, futures and options on futures (including those relating to securities, indexes, foreign currencies and interest rates), and forward contracts. A small investment in derivatives could have a potentially large impact on the fund’s performance. The use of derivatives involves risks different from, or possibly greater than, the risks associated with investing directly in the underlying assets. Derivatives can be highly volatile, illiquid and difficult to value, and there is the risk that changes in the value of a derivative held by the fund will not correlate with the underlying instruments or the fund’s other investments. Derivative instruments also involve the risk that a loss may be sustained as a result of the failure of the counterparty to the derivative instruments to make required payments or otherwise comply with the derivative instruments’ terms.
Leveraging risk. The use of leverage, such as lending portfolio securities, entering into futures contracts or forward currency contracts, entering into reverse repurchase agreements and engaging in forward commitment transactions, may magnify the fund’s gains or losses.
IPO risk. The fund may purchase securities of companies in IPOs.The prices of securities purchased in IPOs can be very volatile.The effect of IPOs on the fund’s performance depends on a variety of factors, including the number of IPOs the fund invests in relative to the size of the fund and whether and to what extent a security purchased in an IPO appreciates or depreciates in value. As a fund’s asset base increases, IPOs often have a diminished effect on such fund’s performance.

Other potential risks

The fund may engage in short-term trading, which could produce higher transaction costs and taxable distributions and lower the fund’s after-tax performance.

The Fund 3

PAST PERFORMANCE

The bar chart and table shown illustrate the risks of investing in the fund.The bar chart shows the fund’s performance for its first full calendar year of operations.The table compares the fund’s average annual total returns to those of the Russell 2500 Value Index, a broad measure of small cap value stock performance. All returns assume reinvestment of dividends and distributions. Of course, past performance (before and after taxes) is no guarantee of future results.

<R>

</R>

Total returns as of 12/31 (%)

Fund shares


Best Quarter:	Q3 ‘08	+1.24%
Worst Quarter:	Q4 ‘08	-27.14%


Average annual total returns as of 12/31/08

		Since
		inception
	1 Year	(7/23/07)

Fund
returns before taxes	-33.33%	-29.82%

Fund
returns after taxes
on distributions	-33.49%	-29.96%

Fund
returns after taxes
on distributions and
sale of fund shares	-21.42%	-24.99%

Russell 2500 Value Index
reflects no deduction for
fees, expenses or taxes	-31.99%	-26.81%

EXPENSES

Fee table

Annual fund operating expenses
(expenses paid from fund assets)
% of average daily net assets


Management fees	.75
Other expenses	2.21
Total	2.96


Expense example
1 Year	3 Years	5 Years	10 Years
$299	$915	$1,557	$3,280

Concepts to understand

Management fee: the fee paid to Dreyfus for managing the fund’s portfolio and assisting in all aspects of the fund’s operations.

For the fiscal year ended September 30, 2008, a portion of the fund’s expenses were waived or reimbursed, reducing the fund’s total annual operating expenses from 2.96% to 1.00%. This waiver is voluntary and may be terminated at any time.

The Fund 5

MANAGEMENT

Investment adviser

Effective on December 1, 2008 (Effective Date), Dreyfus was appointed to serve as the fund’s investment adviser. Prior to the Effective Date, The Boston Company Asset Management, LLC (TBCAM), an affiliate of Dreyfus, was the investment adviser for the fund. For the past fiscal year, TBCAM waived receipt of its investment advisory fee from the fund pursuant to an undertaking in effect. A discussion regarding the basis for the board’s approving the fund’s investment advisory agreement with Dreyfus is available in the fund’s annual report dated September 30, 2008.

Joseph M. Corrado, CFA and Edward R. Walter, CFA are the fund’s primary portfolio managers, positions they have held since the fund’s inception. Mr. Corrado is a senior vice president and is the lead portfolio manager for the U.S. small-cap and small-midcap value equity strategy at TBCAM, where he has been employed since 2003. He is also responsible for conducting research covering the consumer, energy, financial and industrial sectors. Mr.Walter is a senior vice president, portfolio manager for the U.S. small-cap value equity strategy and investment research analyst at TBCAM, where he has been employed since 2003. His research responsibilities include the health care, technology, business services and industrial sectors. Mr. Corrado and Mr. Walter have been employed by Dreyfus since December 2008. As dual employees of Dreyfus and TBCAM, Mr. Corrado and Mr.Walter manage the fund as employees of Dreyfus but use TBCAM’s proprietary investment process.

Distributor

Code of ethics

The Fund 7

FINANCIAL HIGHLIGHTS


		For the period
		July 23, 2007
		(commencement of
	*Year Ended*	operations) to
	*September 30,*	September 30,
	2008	2007
Net Asset Value, Beginning of Year	$19.12	$20.00
From Operations:
Net investment income*^(a)	0.18	0.02
Net realized and unrealized gains (loss) on investments	(2.87)	(0.90)
Total from operations	(2.69)	(0.88)
Less Distributions to Shareholders:
From net investment income	(0.15)	—
Net Asset Value, End of Year	$16.28	$19.12
Total Return^(b)	(14.10)%	(4.40)%^(c)
Ratios/Supplemental Data:
Expenses (to average daily net assets)*	1.00%	1.00%^(d)
Net Investment Income (to average daily net assets)*	1.03%	0.59%^(d)
Portfolio Turnover	73%	18%^(e)
Net Assets, End of Year (000’s omitted)	$6,202	$5,560

______________________

* For the periods indicated,TBCAM, the fund’s former investment adviser, voluntarily agreed not to impose a portion of its investment advisory

fee and/or reimbursed the fund for all or a portion of its operating expenses. If this voluntary action had not been taken, the investment

income per share and the ratios without waivers and reimbursements would have been:


Net investment income (loss) per share^(a)	$(0.16)	$(0.19)
Ratios (to average daily net assets):
Expenses	2.96%	6.85%^(d)
Net investment income (loss)	(0.92)%	(5.27)%^(d)


(a) Calculated based on average shares outstanding.
(b) Total return would have been lower in the absence of expense waivers.
(c)	Returns for periods of less than one year have not been annualized.
(d) Computed on an annualized basis.
(e)	Not annualized.

Your Investment

ACCOUNT POLICIES

Shares of the fund are available only to limited types of investors, and may be purchased by:

bank trust departments, trust companies and insurance companies that have entered into agreements with the fund’s distributor to offer fund shares to their clients
institutional investors acting in a fiduciary, advisory, agency, custodial or similar capacity for qualified or non-qualified employee benefit plans, including pension, profit-sharing and other deferred compensation plans, whether established by corporations, partnerships, non-profit entities, trade or labor unions, or state and local governments, and IRAs set up under Simplified Employee Pension Plans that have entered into agreements with the fund’s distributor to offer fund shares to such plans
law firms or attorneys acting as trustees or executors/administrators
foundations and endowments that make an initial investment in the fund of at least $1 million
sponsors of college savings plans that qualify for tax-exempt treatment under Section 529 of the Internal Revenue Code, that maintain an omnibus account with the fund and do not require shareholder tax reporting or 529 account support responsibilities from the fund’s distributor
advisory fee-based accounts offered through financial intermediaries who, depending on the structure of the selected advisory platform, make fund shares available

Your order will be priced at the next NAV calculated after your order is received in proper form by the fund’s transfer agent or other authorized entity.

Your Investment 9

ACCOUNT POLICIES (continued)

Concept to understand

Net asset value (NAV): a mutual fund’s share price on a given day. A fund’s NAV is calculated by dividing the value of its net assets by the number of its existing shares outstanding.


Minimum investments^†
	Initial	Additional
Regular accounts	$1,000	$100

<R></R>

All investments must be in U.S. dollars. Third-party checks, cash, travelers’ checks or money orders will not be accepted. You may be charged a fee for any check that does not clear.

^†The minimum initial investment for foundations and endowments is

$1 million.

<R></R>

Selling shares

Before selling shares recently purchased by check, please note that:

if you send a written request to sell such shares, the fund may delay sending the proceeds for up to eight business days following the purchase of those shares
the fund will not process wire or telephone redemption requests for up to eight business days following the purchase of those shares


Limitations on selling shares by phone

Proceeds	Minimum	Maximum
sent by	phone	phone

Check	no minimum	$250,000 per day

Wire	$1,000	$500,000 for joint
		accounts every 30 days/
		$20,000 per day

Written sell orders

Some circumstances require written sell orders along with signature guarantees. These include:

amounts of $10,000 or more on accounts whose address has been changed within the last 30 days
requests to send the proceeds to a different payee or address

Written sell orders of $100,000 or more must also be signature guaranteed.

Your Investment 11

ACCOUNT POLICIES (continued)

General policies

The fund reserves the right to:

change or discontinue its exchange privilege, or temporarily suspend the privilege during unusual market conditions
change its minimum or maximum investment amounts
delay sending out redemption proceeds for up to seven days (generally applies only during unusual market conditions or in cases of very large redemptions or excessive trading)
“redeem in kind,” or make payments in securities rather than cash, if the amount redeemed is large enough to affect fund operations (for example, if it exceeds 1% of the fund’s assets)
refuse any purchase or exchange request, including those from any individual or group who, in Dreyfus’ view, is likely to engage in frequent trad- ing

Third-party investments

Small account policy

If your account falls below $500, the fund may ask you to increase your balance. If it is still below $500 after 30 days, the fund may close your account and send you the proceeds.

Your Investment 13

DISTRIBUTIONS AND TAXES

The tax status of your distributions will be detailed in your annual tax statement from the fund. Because everyone’s tax situation is unique, please consult your tax advisor before investing.

EXCHANGE PRIVILEGE

Your Investment 15

For information and other assistance, call toll free
in the U.S. 1-800-645-6561.

Outside the U.S. 516-794-5452.

Make checks payable to: The Dreyfus Family of Funds.

NOTES

For More Information

Dreyfus/The Boston Company

Small Cap Value Fund II

A series of Dreyfus Investment Funds

SEC file number: 811-4813

More information on this fund is available free upon request, including the following:

Annual/Semiannual Report

Statement of Additional Information (SAI)

Portfolio Holdings

A complete description of the fund’s policies and procedures with respect to the disclosure of the fund’s portfolio securities is available in the fund’s SAI.

To obtain information:

By telephone

Call your financial representative or 1-800-645-6561

By mail Write to:

The Dreyfus Family of Funds

144 Glenn Curtiss Boulevard

Uniondale, NY 11556-0144

By E-mail Send your request to info@dreyfus.com

On the Internet Text-only versions of certain fund documents can be viewed online or downloaded from:

SEC http://www.sec.gov

Dreyfus http://www.dreyfus.com