<TABLE> <S> <C>

<ARTICLE> 6
<CIK> 0000202679
<NAME> PIONEER TAX-FREE INCOME FUND
<SERIES>
   <NUMBER> 001
   <NAME> PIONEER TAX-FREE INCOME FUND CLASS A
<CURRENCY> US

<S>                             <C>
<PERIOD-TYPE>                   YEAR
<FISCAL-YEAR-END>                          DEC-31-1999
<PERIOD-END>                               DEC-31-1999
<EXCHANGE-RATE> 1
<INVESTMENTS-AT-COST>                        385842974
<INVESTMENTS-AT-VALUE>                       380543183
<RECEIVABLES>                                  7079426
<ASSETS-OTHER>                                   11456
<OTHER-ITEMS-ASSETS>                                 0
<TOTAL-ASSETS>                               387634065
<PAYABLE-FOR-SECURITIES>                       2995911
<SENIOR-LONG-TERM-DEBT>                              0
<OTHER-ITEMS-LIABILITIES>                      1054516
<TOTAL-LIABILITIES>                            4050427
<SENIOR-EQUITY>                                      0
<PAID-IN-CAPITAL-COMMON>                     391302853
<SHARES-COMMON-STOCK>                         33560680
<SHARES-COMMON-PRIOR>                         32730448
<ACCUMULATED-NII-CURRENT>                        17815
<OVERDISTRIBUTION-NII>                               0
<ACCUMULATED-NET-GAINS>                              0
<OVERDISTRIBUTION-GAINS>                       2437239
<ACCUM-APPREC-OR-DEPREC>                     (5299791)
<NET-ASSETS>                                 383583638
<DIVIDEND-INCOME>                                    0
<INTEREST-INCOME>                             22372870
<OTHER-INCOME>                                       0
<EXPENSES-NET>                                 3958527
<NET-INVESTMENT-INCOME>                       18414343
<REALIZED-GAINS-CURRENT>                     (2437239)
<APPREC-INCREASE-CURRENT>                   (32832549)
<NET-CHANGE-FROM-OPS>                       (16855445)
<EQUALIZATION>                                       0
<DISTRIBUTIONS-OF-INCOME>                     17809302
<DISTRIBUTIONS-OF-GAINS>                        784680
<DISTRIBUTIONS-OTHER>                                0
<NUMBER-OF-SHARES-SOLD>                        7543435
<NUMBER-OF-SHARES-REDEEMED>                    7867060
<SHARES-REINVESTED>                            1153857
<NET-CHANGE-IN-ASSETS>                      (23858681)
<ACCUMULATED-NII-PRIOR>                          35920
<ACCUMULATED-GAINS-PRIOR>                       816664
<OVERDISTRIB-NII-PRIOR>                              0
<OVERDIST-NET-GAINS-PRIOR>                           0
<GROSS-ADVISORY-FEES>                          2005180
<INTEREST-EXPENSE>                                   0
<GROSS-EXPENSE>                                4025823
<AVERAGE-NET-ASSETS>                         401037897
<PER-SHARE-NAV-BEGIN>                            12.02
<PER-SHARE-NII>                                   0.51
<PER-SHARE-GAIN-APPREC>                         (1.02)
<PER-SHARE-DIVIDEND>                              0.51
<PER-SHARE-DISTRIBUTIONS>                         0.02
<RETURNS-OF-CAPITAL>                                 0
<PER-SHARE-NAV-END>                              10.98
<EXPENSE-RATIO>                                   0.93


</TABLE>