<TABLE> <S> <C>
<ARTICLE> 6
<RESTATED>
<CIK> 0000036405
<NAME> VANGUARD INDEX FUNDS
<SERIES>
<NUMBER> 051
<NAME> VANGUARD GROWTH INDEX FUND - INVESTOR SHARES
<MULTIPLIER> 1000
<CURRENCY> US
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-2000
<PERIOD-START> JAN-01-2000
<PERIOD-END> JUN-30-2000
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<INVESTMENTS-AT-VALUE> 17284154
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<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 18540940
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<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 150244
<TOTAL-LIABILITIES> 1369371
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 12170983
<SHARES-COMMON-STOCK> 408160
<SHARES-COMMON-PRIOR> 386301
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 7923
<ACCUMULATED-NET-GAINS> (531780)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 5540288
<NET-ASSETS> 16476106
<DIVIDEND-INCOME> 44047
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<OTHER-INCOME> 130
<EXPENSES-NET> 17378
<NET-INVESTMENT-INCOME> 27501
<REALIZED-GAINS-CURRENT> (290220)
<APPREC-INCREASE-CURRENT> 706406
<NET-CHANGE-FROM-OPS> 443687
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 28141
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 84178
<NUMBER-OF-SHARES-REDEEMED> 62934
<SHARES-REINVESTED> 615
<NET-CHANGE-IN-ASSETS> 1487018
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (241560)
<OVERDISTRIB-NII-PRIOR> 5864
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 84
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<AVERAGE-NET-ASSETS> 15557723
<PER-SHARE-NAV-BEGIN> 39.43
<PER-SHARE-NII> 0.07
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<PER-SHARE-DIVIDEND> 0.07
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 40.37
<EXPENSE-RATIO> 0.22
</TABLE>
