<PAGE>
SUPPLEMENT DATED MARCH 26, 1997
TO THE PROSPECTUS DATED MAY 1, 1996
EQUITY GROWTH PORTFOLIO
EMERGING GROWTH PORTFOLIO
MICROCAP PORTFOLIO
AGGRESSIVE EQUITY PORTFOLIO
PORTFOLIOS OF THE
MORGAN STANLEY INSTITUTIONAL FUND, INC.
P.O. BOX 2798
BOSTON, MASSACHUSETTS
02208-2798
-------------
The Prospectus is hereby amended and supplemented to reflect the resignation
of Dennis G. Sherva as Portfolio Manager of the Emerging Growth Portfolio.
Therefore, effective April 1, 1997, Kurt A. Feuerman, Christopher R. Blair and
Daniel R. Lascano are assuming the positions of Portfolio Managers of the
Emerging Growth Portfolio. Accordingly, the first paragraph on Page 26 is hereby
deleted and replaced with the following:
EMERGING GROWTH PORTFOLIO -- KURT A. FEUERMAN, DANIEL R. LASCANO AND
CHRISTOPHER R. BLAIR. Information about Mr. Feuerman is included under the
Equity Growth Portfolio above.
Daniel Lascano is a Vice President of Morgan Stanley Asset Management. He
joined the Firm in 1993 as an equity analyst. Prior to joining MSAM, Mr. Lascano
worked at Morgan Stanley & Co. as a research assistant to Kurt Feuerman. Mr.
Lascano graduated from the University of California at Berkeley with a B.A. in
Economics and Statistics.
Christopher Blair joined Morgan Stanley Asset Management in 1993 as a
Security Analyst in the Emerging Growth Stock Group. He was elected Vice
President in 1996. Prior to joining MSAM, he was a Financial Analyst for two
years in Morgan Stanley's Corporate Finance Department, where he focused on the
telecommunications and technology sectors. Mr. Blair graduated with Distinction
from McGill University with a B.A. in Economics and Political Science. Mr.
Feuerman, Mr. Lascano and Mr. Blair have shared primary responsibility for
managing the Portfolio's assets since April 1997.
--------------
PLEASE RETAIN THIS SUPPLEMENT FOR FUTURE REFERENCE.