EXHIBIT 32 CERTIFICATIONS OF CHIEF EXECUTIVE OFFICER AND CHIEF FINANCIAL OFFICER PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the Quarterly Report of Neurocrine Biosciences, Inc. (the "Company") on Form 10-Q for the period ended June 30, 2003 as filed with the Securities and Exchange Commission on the date hereof (the "Report"), I, Gary A. Lyons, President and Chief Executive Officer of the Company, certify, pursuant to 18 U.S.C. 1350, as adopted pursuant to 906 of the Sarbanes-Oxley Act of 2002, that, to my knowledge: (1) The Report 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. Date August 8, 2003 By: /s/ Gary A. Lyons Name: Gary A. Lyons Title: President and Chief Executive Officer In connection with the Quarterly Report of Neurocrine Biosciences, Inc. (the "Company") on Form 10-Q for the period ended June 30, 2003 as filed with the Securities and Exchange Commission on the date hereof (the "Report"), I, Paul W. Hawran, Executive Vice President and Chief Financial Officer of the Company, certify, pursuant to 18 U.S.C. 1350, as adopted pursuant to 906 of the Sarbanes-Oxley Act of 2002, that, to my knowledge: (1) The Report 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. Date August 8, 2003 By: /s/ Paul W. Hawran Name: Paul W. Hawran Title: Executive Vice President and Chief Financial Officer