<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
This schedule contains summary financial information extracted from financial
statements of Northwestern Mutual Series Fund, Inc. Money Market portfolio June
30, 2000 and is qualified in its entirety by reference to such financial
statements.
</LEGEND>
<SERIES>
<NUMBER> 11
<NAME> MONEY MARKET PORTFOLIO
<MULTIPLIER> 1000
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-1999
<PERIOD-END> JUN-30-2000
<INVESTMENTS-AT-COST> 384265
<INVESTMENTS-AT-VALUE> 384265
<RECEIVABLES> 350
<ASSETS-OTHER> 28215
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 412830
<PAYABLE-FOR-SECURITIES> 24260
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 27051
<TOTAL-LIABILITIES> 54311
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 358519
<SHARES-COMMON-STOCK> 358536
<SHARES-COMMON-PRIOR> 404298
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 0
<NET-ASSETS> 358519
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 11429
<OTHER-INCOME> 0
<EXPENSES-NET> 563
<NET-INVESTMENT-INCOME> 10866
<REALIZED-GAINS-CURRENT> 0
<APPREC-INCREASE-CURRENT> 0
<NET-CHANGE-FROM-OPS> 10866
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 10866
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 1050021
<NUMBER-OF-SHARES-REDEEMED> 1106584
<SHARES-REINVESTED> 10801
<NET-CHANGE-IN-ASSETS> (45765)
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 563
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 563
<AVERAGE-NET-ASSETS> 0
<PER-SHARE-NAV-BEGIN> 1.0
<PER-SHARE-NII> 0.03
<PER-SHARE-GAIN-APPREC> (0.03)
<PER-SHARE-DIVIDEND> 0
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 1.0
<EXPENSE-RATIO> 0.30
</TABLE>
