Exhibit 32.0 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 Each of the undersigned hereby certifies, in his capacity as an officer of Barr Laboratories, Inc. (the "Company"), for the purposes of 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that to the best of his knowledge: (1) The Annual Report of the Company on Form 10-K/A for the period ended June 30, 2003 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and (2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company. Dated: August 29, 2003 /s/Bruce L. Downey - ------------------ Bruce L. Downey Chief Executive Officer /s/William T. McKee - ------------------- William T. McKee Chief Financial Officer A signed original of this written statement required by Section 906 has been provided to Barr Laboratories, Inc. and will be retained by Barr Laboratories, Inc. and furnished to the Securities and Exchange Commission or its staff upon request.