Certification Pursuant to 18 U.S.C. Section 1350,
                             As Adopted Pursuant to
                  Section 906 of the Sarbanes-Oxley Act of 2002


Name of Issuer: VANGUARD INDEX FUNDS

     In connection with the Report on Form N-CSR of the above-named  issuer that
is accompanied by this certification,  the undersigned hereby certifies,  to his
knowledge, that:

1. The Report fully complies with the  requirements of Section 13(a) or 15(d) of
the Securities Exchange Act of 1934; and

2. The  information  contained in the Report  fairly  presents,  in all material
respects, the financial condition and results of operations of the issuer.


Date:  August 18, 2003                          ________________________________
                                                          John J. Brennan
                                                      Chief Executive Officer










                CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002


Name of Issuer:  VANGUARD INDEX FUNDS

     In connection with the Report on Form N-CSR of the above-named  issuer that
is accompanied by this certification,  the undersigned hereby certifies,  to his
knowledge, that:

1. The Report fully complies with the  requirements of Section 13(a) or 15(d) of
the Securities Exchange Act of 1934; and

2. The  information  contained in the Report  fairly  presents,  in all material
respects, the financial condition and results of operations of the issuer.


Date:  August 18, 2003                          ________________________________
                                                          Thomas J. Higgins
                                                              Treasurer