Filed Pursuant to Rule 497(e)
                                                Registration File No.: 2-82510


                                                              July 30, 2004
                                                                  Supplement

[MORGAN STANLEY LOGO]



              SUPPLEMENT DATED JULY 30, 2004 TO THE PROSPECTUS OF
        MORGAN STANLEY VARIABLE INVESTMENT SERIES--CLASS X AND CLASS Y
                               Dated May 1, 2004

With respect to The Aggressive Equity Portfolio:

The second, third and fourth paragraphs of the "Principal Investment
Strategies" subsection under the section for The Aggressive Equity Portfolio of
the Prospectus are hereby deleted and replaced by the following:

   The Investment Manager follows a flexible investment program in seeking to
   achieve the Portfolio's investment objective. The Investment Manager
   focuses on companies it believes have consistent or rising earnings growth
   records, potential for strong free cash flow and compelling business
   strategies. In this regard, the Investment Manager studies company
   developments, including business strategy and financial results. Valuation
   is viewed in the context of prospects for sustainable earnings and cash
   flow growth. The Investment Manager generally considers selling a portfolio
   holding when it determines that the holding no longer satisfies its
   investment criteria.

The last sentence of the "Principal Investment Strategies" subsection under the
section for The Aggressive Equity Portfolio of the Prospectus is hereby deleted
and replaced by the following:

   Up to 25% of the Portfolio's net assets may be invested in foreign equity
   or fixed-income securities denominated in a foreign currency and traded
   primarily in non-U.S. markets, of which up to 10% may be invested in
   emerging market securities (held either directly or in the form of
   depositary receipts), but of which no more than 5% may be invested in local
   shares.

The fourth paragraph of the "Summary of Principal Risks" subsection under the
section for The Aggressive Equity Portfolio of the Prospectus is hereby deleted
and replaced by the following:

   The Portfolio is subject to the risks associated with investing in foreign
   securities, particularly companies located in emerging market countries.
   These risks include, among other things, the possibility that the Portfolio
   could be adversely affected by changes in currency exchange rates. In
   addition, investments in foreign securities may be adversely affected by,
   among other things, political, social and economic developments abroad.
   Securities issued by companies located in emerging market countries tend to
   be especially volatile and may be less liquid than securities traded in
   developed countries.

With respect to The Equity Portfolio:

The fourth paragraph of the subsection titled "Principal Investment Strategies"
under the section for The Equity Portfolio of the Prospectus is hereby deleted
and replaced by the following:

   The Portfolio may invest in securities of Canadian issuers registered under
   the Securities Exchange Act of 1934 or American Depositary Receipts
   (including up to 10% of the Portfolio's net assets in securities issued by
   foreign issuers organized in emerging market countries held in the form of
   American Depositary Receipts).

The following paragraph is hereby added following the third paragraph of the
subsection titled "Summary of Principal Risks" under the section for The Equity
Portfolio of the Prospectus:

   The Portfolio is subject to the risks associated with investing in foreign
   securities, particularly companies located in emerging market countries.
   These risks include, among other things, the possibility that the Portfolio
   could be adversely affected by changes in currency exchange rates. In
   addition, investments in foreign securities may be adversely affected by,
   among other things, political, social and economic developments abroad.
   Securities issued by companies located in emerging market countries tend to
   be especially volatile and may be less liquid than securities traded in
   developed countries.

With respect to The Global Advantage Portfolio:

The second paragraph of the subsection titled "Principal Investment Strategies"
under the section for The Global Advantage Portfolio of the Prospectus is
hereby deleted and replaced by the following:

   The Portfolio's "Investment Manager," Morgan Stanley Investment Advisors
   Inc. and the Portfolio's "Sub-Advisor," Morgan Stanley Investment
   Management Limited, utilize fundamental research to seek companies that
   they believe have long-term growth potential and/or relatively attractive
   valuations. The Portfolio's portfolio management team generally utilizes a
   bottom-up stock selection process based on fundamental research performed by
   the Sub-Advisor's analysts throughout the world, but also considers global
   industry trends in making certain sector allocations.



                                                              July 30, 2004
                                                                  Supplement

[MORGAN STANLEY LOGO]


The sixteenth paragraph of the subsection titled "Portfolio Management" under
the section for The Global Advantage Portfolio of the Prospectus is hereby
deleted and replaced by the following:


     The Portfolio is managed within the Global Research team. Sandra Yeager is
     a current member of the team.


With respect to The Limited Duration Portfolio:


The following sentence is hereby added following the fourth sentence of the
first paragraph of the "Principal Investment Strategies" subsection under the
section for The Limited Duration Portfolio of the Prospectus:


     The Portfolio may also invest up to 5% of its net assets in targeted return
     index securities ("TRAINS").


With respect to The Quality Income Plus Portfolio:


The following sentence is hereby added following the second sentence of the
last paragraph of the "Principal Investment Strategies" subsection under the
section for The Quality Income Plus Portfolio of the Prospectus:


     The Portfolio may also invest up to 10% of its net assets in targeted
     return index securities ("TRAINS").


With respect to The High Yield Portfolio:


The following sentence is hereby added following the fourth sentence of the
first paragraph of the "Principal Investment Strategies" subsection under the
section for The High Yield Portfolio of the Prospectus:


     The Portfolio may also invest up to 10% of its net assets in targeted
     return index securities ("TRAINS").


With respect to The Strategist Portfolio:


The following sentence is hereby added following the first sentence of the
sixth paragraph of the "Principal Investment Strategies" subsection under the
section for The Strategist Portfolio of the Prospectus:


     The Portfolio may also invest up to 10% of its net assets in targeted
     return index securities ("TRAINS").


The following paragraph is hereby added following the fourth paragraph of the
subsection titled "Additional Investment Strategy Information" under the section
for The Strategist Portfolio:


     TARGETED RETURN INDEX SECURITIES ("TRAINS"). The Limited Duration, Quality
     Income Plus, High Yield and Strategist Portfolios may invest up to 10% (up
     to 5% for The Limited Duration Portfolio) of each Portfolio's net assets in
     TRAINs. A TRAIN is a structured, pooled investment vehicle that permits
     investment in a diversified portfolio of fixed income securities without
     the brokerage and other expenses associated with directly holding small
     positions in individual securities. Since TRAINs are also considered high
     yield securities, investments in TRAINs fall within the limits for
     investments in "junk bonds."


The following paragraph is hereby added following the fifteenth paragraph of the
subsection titled "Additional Risk Information" under the section for The
Strategist Portfolio:


     TRAINS. Certain Portfolios may invest in Targeted Return Index Securities
     ("TRAINs"), which are investment vehicles structured as trusts. Each trust
     represents an undivided investment interest in the pool of securities
     (generally high yield securities) underlying the trust without the
     brokerage and other expenses associated with holding small positions in
     individual securities. TRAINs are not registered under the Securities Act
     of 1933 ("the Securities Act") or the Investment Company Act of 1940 and
     therefore must be held by qualified purchasers and resold to qualified
     institutional buyers pursuant to Rule 144A under the Securities Act. Many
     junk bonds are issued as Rule 144a Securities. Investments in certain
     TRAINs may have the effect of increasing the level of Portfolio illiquidity
     to the extent a Portfolio, at a particular point in time, may be unable to
     find qualified institutional buyers interested in purchasing such
     securities.


              PLEASE RETAIN THIS SUPPLEMENT FOR FUTURE REFERENCE.


                                                                LIT SPT VIS 7/04