March 16, 2000

                            DREYFUS STOCK INDEX FUND
                SUPPLEMENT TO STATEMENT OF ADDITIONAL INFORMATION
                                DATED MAY 1, 1999


1. The following information replaces all contrary information contained in the
sections of the Statement of Additional Information ("SAI") entitled
"Description of the Fund", "Management of the Fund" and "Management
Arrangements":

         Effective March 16, 2000, Dreyfus Service Corporation ("DSC") became
the distributor to the Fund. DSC is located at 200 Park Avenue, New York, NY
10166.

2. The following information replaces the information contained in the section
of the Statement of Additional Information ("SAI") entitled "Management of the
Fund - Officers of the Fund":

Stephen E. Canter,  President.  President,  Chief Operating  Officer,  and Chief
     Investment  Officer of the  Manager,  and an  officer  of other  investment
     companies  advised and  administered  by the Manager.  Mr. Canter also is a
     Director  or  an  Executive   Committee  Member  of  the  other  investment
     management  subsidiaries of Mellon Financial Corporation,  each of which is
     an affiliate of the Manager. He is 54 years old.

Mark N. Jacobs,  Vice President.  Vice President,  General Counsel and Assistant
     Secretary  of the  Manager,  and an officer of other  investment  companies
     advised and administered by the Manager. He is 53 years old.

Joseph   Connolly, Vice President and Treasurer. Director - Mutual Fund
         Accounting of the Manager, and an officer of other investment companies
         advised and administered by the Manager. He is 42 years old.

Michael A. Rosenberg,  Secretary.  Associate General Counsel of the Manager, and
     an officer of other  investment  companies  advised and administered by the
     Manager. He is 40 years old.

Steven F. Newman,  Assistant Secretary.  Associate General Counsel and Assistant
     Secretary  of the  Manager,  and an officer of other  investment  companies
     advised and administered by the Manager. He is 50 years old.

Mark Kornfeld,  Assistant  Secretary.  Assistant General Counsel of the Manager,
     and an officer of other  investment  companies  advised and administered by
     the Manager.  From  September  1993 to October  1998,  Mr.  Kornfeld was an
     Associate  Attorney in the  Litigation  Group of Clifford  Chance  Rogers &
     Wells, LLP. He is 32 years old.

JamesWindels,  Assistant Treasurer.  Senior Treasury Manager of the Manager, and
     an officer of other  investment  companies  advised and administered by the
     Manager. He is 41 years old.

         The address of each Fund officer is 200 Park Avenue, New York, NY
10166.