WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.

<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>                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1999
<PERIOD-END>                               JUN-30-1999
<INVESTMENTS-AT-COST>                        415870855
<INVESTMENTS-AT-VALUE>                       426140737
<RECEIVABLES>                                  7276051
<ASSETS-OTHER>                                    3503
<OTHER-ITEMS-ASSETS>                                 0
<TOTAL-ASSETS>                               433420291
<PAYABLE-FOR-SECURITIES>                             0
<SENIOR-LONG-TERM-DEBT>                              0
<OTHER-ITEMS-LIABILITIES>                      1127403
<TOTAL-LIABILITIES>                            1127403
<SENIOR-EQUITY>                                      0
<PAID-IN-CAPITAL-COMMON>                     420598127
<SHARES-COMMON-STOCK>                         35877459
<SHARES-COMMON-PRIOR>                         32730448
<ACCUMULATED-NII-CURRENT>                            0
<OVERDISTRIBUTION-NII>                           15578
<ACCUMULATED-NET-GAINS>                        1440457
<OVERDISTRIBUTION-GAINS>                             0
<ACCUM-APPREC-OR-DEPREC>                      10269882
<NET-ASSETS>                                 432292888
<DIVIDEND-INCOME>                                    0
<INTEREST-INCOME>                             11018691
<OTHER-INCOME>                                       0
<EXPENSES-NET>                                 1980976
<NET-INVESTMENT-INCOME>                        9037715
<REALIZED-GAINS-CURRENT>                        623793
<APPREC-INCREASE-CURRENT>                   (17262876)
<NET-CHANGE-FROM-OPS>                        (7601368)
<EQUALIZATION>                                       0
<DISTRIBUTIONS-OF-INCOME>                      8789476
<DISTRIBUTIONS-OF-GAINS>                             0
<DISTRIBUTIONS-OTHER>                                0
<NUMBER-OF-SHARES-SOLD>                        5660483
<NUMBER-OF-SHARES-REDEEMED>                    3043661
<SHARES-REINVESTED>                             530189
<NET-CHANGE-IN-ASSETS>                        24850569
<ACCUMULATED-NII-PRIOR>                          35920
<ACCUMULATED-GAINS-PRIOR>                       816664
<OVERDISTRIB-NII-PRIOR>                              0
<OVERDIST-NET-GAINS-PRIOR>                           0
<GROSS-ADVISORY-FEES>                          1004458
<INTEREST-EXPENSE>                                   0
<GROSS-EXPENSE>                                2015082
<AVERAGE-NET-ASSETS>                         409133964
<PER-SHARE-NAV-BEGIN>                            12.02
<PER-SHARE-NII>                                   0.26
<PER-SHARE-GAIN-APPREC>                         (0.51)
<PER-SHARE-DIVIDEND>                              0.26
<PER-SHARE-DISTRIBUTIONS>                            0
<RETURNS-OF-CAPITAL>                                 0
<PER-SHARE-NAV-END>                              11.51
<EXPENSE-RATIO>                                   0.92
[AVG-DEBT-OUTSTANDING]                               0
[AVG-DEBT-PER-SHARE]                                 0


</TABLE>