Exhibit 32.1

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

I, Richard M. Shepperd, the Chief Executive Officer of Bioanalytical Systems, Inc. certify that (i) the Quarterly Report on Form 10-Q for the quarter ended March 31, 2007, (the "Report") fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, and (ii) the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of BASi as of the dates and for the periods set forth therein.



			/s/ Richard M. Shepperd
			Richard M. Shepperd Chief Executive Officer

			Date: May 9, 2007

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

I, Michael R. Cox, Vice President, Finance and Chief Financial Officer of Bioanalytical Systems, Inc. certify that (i) the Quarterly Report on Form 10-Q for the quarter ended March 31, 2007, (the "Report") fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, and (ii) the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of BASi as of the dates and for the periods set forth therein.



			/s/ Michael R. Cox
			Michael R. Cox Vice President, Finance and Chief Financial Officer

			Date: May 9, 2007