<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000036405
<NAME> VANGUARD INDEX FUNDS
<SERIES>
<NUMBER> 061
<NAME> VANGUARD SMALL-CAP 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
<EXCHANGE-RATE> 1
<INVESTMENTS-AT-COST> 4375160
<INVESTMENTS-AT-VALUE> 4724978
<RECEIVABLES> 464436
<ASSETS-OTHER> 807
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 5190221
<PAYABLE-FOR-SECURITIES> 461437
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 140624
<TOTAL-LIABILITIES> 602061
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 3880335
<SHARES-COMMON-STOCK> 169026
<SHARES-COMMON-PRIOR> 150533
<ACCUMULATED-NII-CURRENT> 21127
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 336815
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 349883
<NET-ASSETS> 4096303
<DIVIDEND-INCOME> 24899
<INTEREST-INCOME> 985
<OTHER-INCOME> 2304
<EXPENSES-NET> 5548
<NET-INVESTMENT-INCOME> 22640
<REALIZED-GAINS-CURRENT> 338390
<APPREC-INCREASE-CURRENT> (238822)
<NET-CHANGE-FROM-OPS> 122208
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0
<DISTRIBUTIONS-OF-GAINS> 34923
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 37559
<NUMBER-OF-SHARES-REDEEMED> 20284
<SHARES-REINVESTED> 1217
<NET-CHANGE-IN-ASSETS> 620367
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 37017
<OVERDISTRIB-NII-PRIOR> 1513
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 84
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 5548
<AVERAGE-NET-ASSETS> 3889634
<PER-SHARE-NAV-BEGIN> 23.60
<PER-SHARE-NII> 0.119
<PER-SHARE-GAIN-APPREC> 0.726
<PER-SHARE-DIVIDEND> 0
<PER-SHARE-DISTRIBUTIONS> 0.215
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 24.23
<EXPENSE-RATIO> 0.27
</TABLE>
