Exhibit 23.01 Consent of Independent Auditors We consent to the incorporation by reference in the Registration Statement (Form S-8) pertaining to the 1997 Bioanalytical Systems, Inc. Outside Director Stock Option Plan of our report dated October 31, 1997 (except for Note 10, as to which the date is November 21, 1997) with respect to the consolidated financial statements of Bioanalytical Systems, Inc. included in its Registration Statement on Form S-1 (No. 333-36429) dated November 24, 1997 filed with the Securities and Exchange Commission. /s/ Ernst & Young LLP Indianapolis, Indiana June 1, 1998