CERTIFICATION PURSUANT TO SECTION 906
                                       OF
                             THE SARBANES OXLEY ACT



The undersigned hereby certifies, to the best of his knowledge, that:

     1.   The Form N-CSR of BARON  INVESTMENT FUNDS TRUST (the "Issuer") and its
          separate  series for the period  ended March 31,  2005 (the  "Report")
          fully complies with the  requirements of Section 13(a) or 15(d) of the
          Securities Exchange Act of 1934, as applicable; and

     2.   The  information  contained  in the  Report  fairly  presents,  in all
          material respects,  the financial  condition and results of operations
          of the Issuer.



By:  /s/ Ronald Baron                                Date:    June 9, 2005
     ---------------------------
         Ronald Baron
         Chief Executive Officer







                      CERTIFICATION PURSUANT TO SECTION 906
                                       OF
                             THE SARBANES OXLEY ACT



The undersigned hereby certifies, to the best of her knowledge, that:

     1.   The Form N-CSR of BARON  INVESTMENT FUNDS TRUST (the "Issuer") and its
          separate  series for the period  ended March 31,  2005 (the  "Report")
          fully complies with the  requirements of Section 13(a) or 15(d) of the
          Securities Exchange Act of 1934, as applicable; and

     2.   The  information  contained  in the  Report  fairly  presents,  in all
          material respects,  the financial  condition and results of operations
          of the Issuer.


By:  /s/ Peggy Wong                                Date:    June 9, 2005
     -----------------------------------------
         Peggy Wong
         Treasurer and Chief Financial Officer