BLACKROCK U.S. OPPORTUNITIES PORTFOLIO

Fund Overview

Key Facts About BlackRock U.S. Opportunities Portfolio

Investment Objective

The investment objective of BlackRock U.S. Opportunities Portfolio ("U.S. Opportunities" or the "Fund"), a series of BlackRock Funds^SM (the "Trust"), is to provide long-term capital appreciation.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold Class R Shares of U.S. Opportunities.

Annual Fund Operating Expenses
(expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses -		BLACKROCK U.S. OPPORTUNITIES PORTFOLIO Class R Shares
Management Fee		1.04%
Distribution and/or Service (12b-1) Fees		0.50%
Other Expenses	^[1]	0.30%
Acquired Fund Fees and Expenses		0.01%
Total Annual Fund Operating Expenses		1.85%
Fee Waivers and/or Expense Reimbursements	^[2]
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	^[2]	1.85%

[1]

Other Expenses are based on estimated amounts for the current fiscal year.

[2]

As described in the "Management of the Funds" section of the Fund's prospectus on pages 55-63, BlackRock Advisors, LLC ("BlackRock") has contractually agreed to waive and/or reimburse fees or expenses in order to limit Total Annual Fund Operating Expenses After Fee Waivers and Expense Reimbursements (excluding Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses) to 2.39% of average daily net assets until February 1, 2013. The agreement may be terminated upon 90 days' notice by a majority of the non-interested trustees of the Trust or by a vote of a majority of the outstanding voting securities of the Fund.

Example:

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example - (USD $)	1 Year	3 Years
BLACKROCK U.S. OPPORTUNITIES PORTFOLIO Class R Shares	188	582

Portfolio Turnover:

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 120% of the average value of its portfolio.

Principal Investment Strategies of the Fund

Under normal market conditions, U.S. Opportunities invests at least 80% of its net assets in equity securities issued by U.S. emerging capitalization companies with relatively attractive earnings growth potential and valuation. Although a universal definition of emerging capitalization companies does not exist, the Fund generally defines these companies, at the time of the Fund's investment, as those with market capitalizations equal to those within the universe of the Russell Midcap^® Index stocks (between approximately $519 million and $17.9 billion as of June 30, 2011, the most recent rebalance date). In the future, the Fund may define emerging capitalization companies using a different index or classification system.

The Fund primarily buys common stock but can also invest in preferred stock and convertible securities. From time to time the Fund may invest in shares of companies through initial public offerings ("IPOs").

The Fund may, when consistent with the Fund's investment objective, buy or sell options or futures on a security or an index of securities (collectively, commonly known as derivatives). The primary purpose of using derivatives is to attempt to reduce risk to the Fund as a whole (hedge), but they may also be used to maintain liquidity and commit cash pending investment. The Fund also may, but under normal market conditions generally does not intend to, use derivatives for speculation to increase returns.

Principal Risks of Investing in the Fund

Risk is inherent in all investing. The value of your investment in U.S. Opportunities, as well as the amount of return you receive on your investment, may fluctuate significantly from day to day and over time. You may lose part or all of your investment in the Fund or your investment may not perform as well as other similar investments. The following is a summary description of certain risks of investing in the Fund.

Convertible Securities Risk — The market value of a convertible security performs like that of a regular debt security; that is, if market interest rates rise, the value of a convertible security usually falls. In addition, convertible securities are subject to the risk that the issuer will not be able to pay interest or dividends when due, and their market value may change based on changes in the issuer's credit rating or the market's perception of the issuer's creditworthiness. Since it derives a portion of its value from the common stock into which it may be converted, a convertible security is also subject to the same types of market and issuer risks that apply to the underlying common stock.

Derivatives Risk — The Fund's use of derivatives may reduce the Fund's returns and/or increase volatility. Volatility is defined as the characteristic of a security, an index or a market to fluctuate significantly in price within a short time period. Derivatives are also subject to counterparty risk, which is the risk that the other party in the transaction will not fulfill its contractual obligation. A risk of the Fund's use of derivatives is that the fluctuations in their values may not correlate perfectly with the overall securities markets. The possible lack of a liquid secondary market for derivatives and the resulting inability of the Fund to sell or otherwise close a derivatives position could expose the Fund to losses and could make derivatives more difficult for the Fund to value accurately. Derivatives may give rise to a form of leverage and may expose the Fund to greater risk and increase its costs. Recent legislation calls for new regulation of the derivatives markets. The extent and impact of the regulation is not yet known and may not be known for some time. New regulation may make derivatives more costly, may limit the availability of derivatives, or may otherwise adversely affect the value or performance of derivatives.

Equity Securities Risk — Stock markets are volatile. The price of the equity securities fluctuates based on changes in a company's financial condition and overall market and economic conditions.

Investment Style Risk — Under certain market conditions, growth investments have performed better during the later stages of economic expansion. Therefore, the growth investment style may over time go in and out of favor. At times when the investment style used by the Fund is out of favor, the Fund may underperform other equity funds that use different investment styles.

Market Risk and Selection Risk — Market risk is the risk that one or more markets in which the Fund invests will go down in value, including the possibility that the markets will go down sharply and unpredictably. Selection risk is the risk that the securities selected by Fund management will underperform the markets, the relevant indices or the securities selected by other funds with similar investment objectives and investment strategies. This means you may lose money.

Mid-Cap Securities Risk — The securities of mid-cap companies generally trade in lower volumes and are generally subject to greater and less predictable price changes than the securities of larger capitalization companies.

"New Issues" Risk — New issues are initial public offerings of U.S. securities. Securities issued in IPOs have no trading history, and information about the companies may be available for very limited periods. In addition, the prices of securities sold in IPOs may be highly volatile or may decline shortly after the initial public offering.

Small Cap and Emerging Growth Securities Risk — Small cap or emerging growth companies may have limited product lines or markets. They may be less financially secure than larger, more established companies. They may depend on a more limited management group than larger capitalized companies.

Performance Information

Class R Shares do not have a performance history as of the date of this prospectus. As a result, the chart and table give you a picture of the long-term performance of U.S. Opportunities for Investor A Shares, which are not offered in this prospectus. Investor A Shares would have annual returns substantially similar to Class R Shares differing only to the extent that Investor A and Class R Shares have different expenses. The actual return of Class R Shares would generally be lower than that of Investor A Shares because Class R Shares are subject to higher distribution and/or service (12b-1) fees than Investor A Shares.

This information shows you how the Fund's performance has varied year by year and provides some indication of the risks of investing in the Fund. The table compares the average annual total returns of the Fund's shares with that of the Russell Midcap^® Index. As with all such investments, past performance (before and after taxes) is not an indication of future results. Sales charges are not reflected in the bar chart. If they were, returns would be less than those shown. However, the table includes all applicable fees and sales charges. If BlackRock and its affiliates had not waived or reimbursed certain Fund expenses during these periods, the Fund's returns would have been lower. Updated information on the Fund's results can be obtained by visiting http://www.blackrock.com/funds or can be obtained by phone at (800) 882-0052.

Investor A Shares
ANNUAL TOTAL RETURNS
BlackRock U.S. Opportunities Portfolio
As of 12/31

During the ten-year period shown in the bar chart, the highest return for a quarter was 19.31% (quarter ended June 30, 2003) and the lowest return for a quarter was –22.42% (quarter ended September 30, 2011).

As of 12/31/11
Average Annual Total Returns

Average Annual Total Returns - BLACKROCK U.S. OPPORTUNITIES PORTFOLIO	1 Year	5 Years	10 Years
Investor A Shares	(14.35%)	2.47%	4.90%
Investor A Shares Return After Taxes on Distributions	(15.80%)	2.07%	4.69%
Investor A Shares Return After Taxes on Distributions and Sale of Shares	(7.59%)	2.09%	4.27%
Russell Midcap Index (Reflects no deduction for fees, expenses or taxes)	(1.55%)	1.41%	6.99%

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) plans or individual retirement accounts. After-tax returns are shown for Investor A Shares only, and the after-tax returns for Class R Shares will vary.