
SMALL COMPANY GROWTH PORTFOLIO (Prospectus Summary): \| SMALL COMPANY GROWTH PORTFOLIO
Small Company Growth Portfolio
Prospectus Supplement October 12, 2011 Morgan Stanley Institutional Fund, Inc. Supplement dated October 12, 2011 to the Morgan Stanley Institutional Fund, Inc. (the "Fund") Prospectus dated August 23, 2011 of: Small Company Growth Portfolio
The second sentence of the sixth paragraph in the section of the Prospectus titled "Portfolio Summary—Small Company Growth Portfolio—Principal Investment Strategies" is hereby deleted and replaced with the following:
The Portfolio's use of derivatives may involve the purchase and sale of derivative instruments such as futures, options, swaps and structured investments, and other related instruments and techniques.
Please retain this supplement for future reference.

SupplementClosingTextBlock

Name:	ck0000836487_Supplementclosingtextblock
Namespace Prefix:	ck0000836487
Data Type:	us-types:textBlockItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	ck0000836487_SupplementTextBlock
Namespace Prefix:	ck0000836487
Data Type:	us-types:textBlockItemType
Balance Type:	na
Period Type:	duration

- Definition

Risk/Return Summary Investment Objectives/Goals Include the following information, in plain English under rule 421(d) under the Securities Act, in the order and subject matter indicated

+ References

Reference 1: 1

-Publisher SEC

-Name Form

-Number N-1A

-Chapter A

-Section 2

+ Details

Name:	rr_RiskReturnHeading
Namespace Prefix:	rr
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Principal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.

+ References

Reference 1: 1

-Publisher SEC

-Name Form

-Number N-1A

-Chapter A

-Section 4

-Subsection a

+ Details

Name:	rr_StrategyHeading
Namespace Prefix:	rr
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

+ References

Reference 1: 1

-Publisher SEC

-Name Form

-Number N-1A

-Chapter A

-Section 4

-Subsection a

+ Details

Name:	rr_StrategyNarrativeTextBlock
Namespace Prefix:	rr
Data Type:	us-types:textBlockItemType
Balance Type:	na
Period Type:	duration