Opportunity Portfolio

Opportunity Portfolio

Objective

The Opportunity Portfolio seeks long-term capital appreciation.

Fees and Expenses

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Portfolio. For shareholders of Class P and Class H shares, you may qualify for sales charge discounts if the cumulative net asset value ("NAV") of Class P or Class H shares of the Portfolio purchased in a single transaction, together with the NAV of all Class P or Class H shares of portfolios of Morgan Stanley Institutional Fund, Inc. (the "Fund") or portfolios of Morgan Stanley Institutional Fund Trust held in related accounts, amounts to $25,000 or more with respect to Class P and $50,000 or more with respect to Class H. More information about these and other discounts is available from your financial adviser and in the "Shareholder Information—How To Purchase Class P and Class H Shares" section on page 25 of this Prospectus.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees Opportunity Portfolio	Class I	Class P	Class H	Class L
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	none	5.25%	4.75%	none

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

Annual Fund Operating Expenses Opportunity Portfolio		Class I	Class P	Class H	Class L
Advisory Fee		0.50%	0.50%	0.50%	0.50%
Distribution and/or Shareholder Service (12b-1) Fee		none	0.25%	0.25%	0.75%
Other Expenses		0.41%	0.41%	0.41%	0.41%
Total Annual Portfolio Operating Expenses	[1]	0.91%	1.16%	1.16%	1.66%
Fee Waiver and/or Expense Reimbursement	[1]	0.03%	0.03%	0.03%	0.03%
Total Annual Portfolio Operating Expenses After Fee Waiver and/or Expense Reimbursement	[1]	0.88%	1.13%	1.13%	1.63%

Example

The example below is intended to help you compare the cost of investing in the Portfolio with the cost of investing in other mutual funds.

The example assumes that you invest $10,000 in the Portfolio, your investment has a 5% return each year and that the Portfolio'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 Opportunity Portfolio (USD $)	1 Year	3 Years	5 Years	10 Years
Class I	90	281	488	1,084
Class P	634	865	1,115	1,827
Class H	585	817	1,068	1,784
Class L	166	514	887	1,933

Portfolio Turnover

The Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Portfolio shares are held in a taxable account. These costs, which are not reflected in Total Annual Portfolio Operating Expenses or in the Example, affect Portfolio performance. During the most recent fiscal year, the Portfolio's portfolio turnover rate was 24% of the average value of its portfolio.

Principal Investment Strategies

Under normal market conditions, the Adviser seeks to achieve the Portfolio's investment objective by investing primarily in established and emerging franchise companies with capitalizations within the range of companies included in the Russell 1000® Growth Index. The Adviser emphasizes a bottom-up stock selection process, seeking attractive growth investments on an individual company basis. In selecting securities for investment, the Adviser seeks companies with the potential for strong free cash flow generation and that the Adviser believes are undervalued at the time of purchase. The Adviser typically favors companies it believes have consistent or rising earnings growth records and compelling business strategies. The Adviser generally considers selling a portfolio holding when it determines that the holding no longer satisfies its investment criteria.

Under normal market conditions, the Portfolio invests at least 80% of its net assets (plus any borrowings for investment purposes) in equity securities. This policy may be changed without shareholder approval; however, you will be notified in writing of any changes.

The Portfolio's equity investments may include common and preferred stocks, convertible securities and equity-linked securities, rights and warrants to purchase common stocks, depositary receipts, exchange-traded funds ("ETFs"), limited partnership interests and other specialty securities having equity features. The Portfolio may also invest in foreign securities, which may include emerging market securities. The Portfolio may invest in privately placed and restricted securities.

The Portfolio may utilize foreign currency forward exchange contracts, which are derivatives, in connection with its investments in foreign securities.

Principal Risks

There is no assurance that the Portfolio will achieve its investment objective and you can lose money investing in this Portfolio. The principal risks of investing in the Portfolio include:

•  Equity Securities. In general, prices of equity securities are more volatile than those of fixed income securities. The prices of equity securities fluctuate, and sometimes widely fluctuate, in response to activities specific to the issuer of the security as well as factors unrelated to the fundamental condition of the issuer, including general market, economic and political conditions. To the extent that the Portfolio invests in convertible securities, and the convertible security's investment value is greater than its conversion value, its price will be likely to increase when interest rates fall and decrease when interest rates rise. If the conversion value exceeds the investment value, the price of the convertible security will tend to fluctuate directly with the price of the underlying equity security.

•  Foreign and Emerging Market Securities. Investments in foreign markets entail special risks such as currency, political, economic and market risks. There also may be greater market volatility, less reliable financial information, higher transaction and custody costs, decreased market liquidity and less government and exchange regulation associated with investments in foreign markets. In addition, investments in certain foreign markets, which have historically been considered stable, may become more volatile and subject to increased risk due to ongoing developments and changing conditions in such markets. Moreover, the growing interconnectivity of global economies and financial markets has increased the probability that adverse developments and conditions in one country or region will affect the stability of economies and financial markets in other countries or regions. The risks of investing in emerging market countries are greater than risks associated with investments in foreign developed countries. In addition, the Portfolio's investments may be denominated in foreign currencies and therefore, to the extent unhedged, the value of the investment will fluctuate with the U.S. dollar exchange rates. To the extent hedged by use of foreign currency forward exchange contracts, the precise matching of foreign currency forward exchange contract amounts and the value of the securities involved will not generally be possible because the future value of such securities in foreign currencies will change as a consequence of market movements in the value of those securities between the date on which the contract is entered into and the date it matures. There is additional risk that such transactions reduce or preclude the opportunity for if the value of the currency should move in the direction opposite to the position taken gain and that foreign currency forward exchange contracts create exposure to currencies in which the Portfolio's securities are not denominated. The use of foreign currency forward exchange contracts involves the risk of loss from the insolvency or bankruptcy of the counterparty to the contract or the failure of the counterparty to make payments or otherwise comply with the terms of the contract.

•  Privately Placed and Restricted Securities. The Portfolio's investments may also include privately placed securities, which are subject to resale restrictions. These securities will have the effect of increasing the level of Portfolio illiquidity to the extent the Portfolio may be unable to sell or transfer these securities due to restrictions on transfers or on the ability to find buyers interested in purchasing the securities. The illiquidity of the market, as well as the lack of publicly available information regarding these securities, may also adversely affect the ability to arrive at a fair value for certain securities at certain times and could make it difficult for the Portfolio to sell certain securities.

Shares of the Portfolio are not bank deposits and are not guaranteed or insured by the Federal Deposit Insurance Corporation or any other government agency.

Performance Information

Pursuant to an agreement and plan of reorganization between the Fund, on behalf of the Portfolio, and Van Kampen Series Fund, Inc., on behalf of the Van Kampen Equity Growth Fund (the "Predecessor Fund"), on May 21, 2010 the Portfolio acquired substantially all of the assets and substantially all of the liabilities of the Predecessor Fund in exchange for Class I, Class H and Class L shares of the Portfolio (the "Reorganization").

Pursuant to the Reorganization, Class A and Class B shareholders of the Predecessor Fund received Class H shares of the Portfolio, and Class C and Class I shareholders of the Predecessor Fund received Class L and Class I shares, respectively, of the Portfolio. As a result of the Reorganization, the Portfolio is the accounting successor of the Predecessor Fund. The historical performance information shown below reflects, for the period prior to the Reorganization, the historical performance of the Class A, Class C and Class I shares of the Predecessor Fund.

The bar chart and table below provide some indication of the risks of investing in the Portfolio by showing changes in the Portfolio's Class H shares'* performance from year-to-year and by showing how the Portfolio's average annual returns for the past one, five and 10 year periods and since inception compare with those of a broad measure of market performance, as well as an index that represents a group of similar mutual funds, over time. The performance of the other Classes, which is shown in the table below, will differ because the Classes have different ongoing fees. The performance information in the bar chart does not reflect the deduction of sales charges; if these amounts were reflected, returns would be less than shown. The Portfolio's returns in the table include the maximum applicable sales charge for Class P and Class H and assume you sold your shares at the end of each period (unless otherwise noted). The Portfolio's past performance, before and after taxes, is not necessarily an indication of how the Portfolio will perform in the future. Updated performance information is available online at www.morganstanley.com/im.

Annual Total Returns*-Calendar Years

*Performance shown for the Portfolio's Class H shares reflects the performance of the Class A shares of the Predecessor Fund for periods prior to May 21, 2010.

High Quarter	6/30/09	24.05	%
Low Quarter	12/31/08	–28.83	%

Average Annual Total Returns (for the calendar periods ended December 31, 2012)

Average Annual Returns Opportunity Portfolio		Average Annual Returns, Past One Year	Average Annual Returns, Past Five Years	Average Annual Returns, Past Ten Years	Average Annual Returns, Since Inception	Average Annual Returns, Inception Date
Class I	[1]	9.43%	2.87%		6.96%	Aug. 12, 2005
Class H	[1]	4.03%	1.61%	7.79%	3.70%	May 28, 1998
Class L	[1]	8.62%	1.97%	7.62%	3.35%	May 28, 1998
Class P	[2]	3.45%			10.13%	May 21, 2010
After Taxes on Distributions Class H	[1]	4.03%	1.61%	7.79%	3.50%
After Taxes on Distributions and Sale of Portfolio Shares Class H	[1]	2.62%	1.38%	6.90%	3.13%
Russell 1000® Growth Index Class I Comparison (reflects no deduction for fees, expenses or taxes)	[3]	15.26%	3.12%		5.28%	Aug. 12, 2005
Lipper Multi-Cap Growth Funds Index Class I Comparison (reflects no deduction for taxes)	[4]	15.88%	1.41%		4.60%	Aug. 12, 2005
Russell 1000® Growth Index Class L Comparison (reflects no deduction for fees, expenses or taxes)	[3]	15.26%	3.12%	7.52%	2.75%	May 28, 1998
Lipper Multi-Cap Growth Funds Index Class L Comparison (reflects no deduction for taxes)	[4]	15.88%	1.41%	8.06%	3.46%	May 28, 1998
Russell 1000® Growth Index Class P Comparison (reflects no deduction for fees, expenses or taxes)	[3]	15.26%			14.27%	May 21, 2010
Lipper Multi-Cap Growth Funds Index Class P Comparison (reflects no deduction for taxes)	[4]	15.88%			12.51%	May 21, 2010

The after-tax returns shown in the table above are calculated using the historical highest individual federal marginal income tax rates during the period shown and do not reflect the impact of state and local taxes. After-tax returns for the Portfolio's other Classes will vary from Class I shares' returns. Actual after-tax returns depend on the investor's tax situation and may differ from those shown, and after-tax returns are not relevant to investors who hold their Portfolio shares through tax deferred arrangements such as 401(k) plans or individual retirement accounts. After-tax returns may be higher than before-tax returns due to an assumed benefit from capital losses that would have been realized had Portfolio shares been sold at the end of the relevant periods, as applicable.

[1] The Portfolio's "Adviser," Morgan Stanley Investment Management Inc., has agreed to reduce its advisory fee and/or reimburse the Portfolio so that Total Annual Portfolio Operating Expenses, excluding certain investment related expenses, taxes, interest and other extraordinary expenses (including litigation), will not exceed 0.88% for Class I, 1.13% for Class P, 1.13% for Class H and 1.63% for Class L. The fee waivers and/or expense reimbursements will continue for at least one year or until such time as the Fund's Board of Directors acts to discontinue all or a portion of such waivers and/or reimbursements when it deems such action is appropriate.

[1] Performance shown for the Portfolio's Class I, Class H and Class L shares reflects the performance of the Class I, Class A and Class C shares, respectively, of the Predecessor Fund for periods prior to May 21, 2010.

[2] The historical performance of Class P shares has been restated to reflect the current maximum initial sales charge of 5.25%.

[3] The Russell 1000 Growth Index measures the performance of the large-cap growth segment of the U.S. equity universe. It includes those Russell 1000 Index companies with higher price-to-book ratios and higher forecasted growth values. The Russell 1000 Index is an index of approximately 1,000 of the largest U.S. companies based on a combination of market capitalization and current index membership. It is not possible to invest directly in an index.

[4] The Lipper Multi-Cap Growth Funds Index is an equally weighted performance index of the largest qualifying funds (based on net assets) in the Lipper Multi-Cap Growth Funds classification. There are currently 30 funds represented in this Index.