<TABLE> <S> <C>

<ARTICLE> 6
<CIK> 0000202679
<NAME> PIONEER TAX-FREE INCOME FUND
<SERIES>
   <NUMBER> 001
   <NAME> PIONEER TAX-FREE INCOME FUND CLASS A
       
<S>                             <C>
<PERIOD-TYPE>                   YEAR
<FISCAL-YEAR-END>                          DEC-31-1998
<PERIOD-END>                               DEC-31-1998
<INVESTMENTS-AT-COST>                        376054944
<INVESTMENTS-AT-VALUE>                       403587702
<RECEIVABLES>                                  6515231
<ASSETS-OTHER>                                    4373
<OTHER-ITEMS-ASSETS>                                 0
<TOTAL-ASSETS>                               410107306
<PAYABLE-FOR-SECURITIES>                       1620557
<SENIOR-LONG-TERM-DEBT>                              0
<OTHER-ITEMS-LIABILITIES>                      1044430
<TOTAL-LIABILITIES>                            2664987
<SENIOR-EQUITY>                                      0
<PAID-IN-CAPITAL-COMMON>                     379056977
<SHARES-COMMON-STOCK>                         32730448
<SHARES-COMMON-PRIOR>                         34002418
<ACCUMULATED-NII-CURRENT>                        35920
<OVERDISTRIBUTION-NII>                               0
<ACCUMULATED-NET-GAINS>                         816664
<OVERDISTRIBUTION-GAINS>                             0
<ACCUM-APPREC-OR-DEPREC>                      27532758
<NET-ASSETS>                                 407442319
<DIVIDEND-INCOME>                                    0
<INTEREST-INCOME>                             22257400
<OTHER-INCOME>                                       0
<EXPENSES-NET>                                 3856065
<NET-INVESTMENT-INCOME>                       18401335
<REALIZED-GAINS-CURRENT>                      12007205
<APPREC-INCREASE-CURRENT>                    (5848257)
<NET-CHANGE-FROM-OPS>                          6158948
<EQUALIZATION>                                       0
<DISTRIBUTIONS-OF-INCOME>                     17980683
<DISTRIBUTIONS-OF-GAINS>                      10813748
<DISTRIBUTIONS-OTHER>                                0
<NUMBER-OF-SHARES-SOLD>                        2187317
<NUMBER-OF-SHARES-REDEEMED>                    5221565
<SHARES-REINVESTED>                            1762278
<NET-CHANGE-IN-ASSETS>                      (13644893)
<ACCUMULATED-NII-PRIOR>                              0
<ACCUMULATED-GAINS-PRIOR>                            0
<OVERDISTRIB-NII-PRIOR>                           2217
<OVERDIST-NET-GAINS-PRIOR>                           0
<GROSS-ADVISORY-FEES>                          1991781
<INTEREST-EXPENSE>                                   0
<GROSS-EXPENSE>                                3910262
<AVERAGE-NET-ASSETS>                         401360399
<PER-SHARE-NAV-BEGIN>                            12.17
<PER-SHARE-NII>                                   0.55
<PER-SHARE-GAIN-APPREC>                           0.19
<PER-SHARE-DIVIDEND>                              0.55
<PER-SHARE-DISTRIBUTIONS>                         0.34
<RETURNS-OF-CAPITAL>                                 0
<PER-SHARE-NAV-END>                              12.02
<EXPENSE-RATIO>                                   0.93
<AVG-DEBT-OUTSTANDING>                               0
<AVG-DEBT-PER-SHARE>                                 0
        

</TABLE>