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

In connection with the Quarterly Report of Avanir Pharmaceuticals (the
"Company") on Form 10-Q for the period ending June 30, 2004, as filed with the
Securities and Exchange Commission on the date hereof (the "Report"), I, Gerald
J. Yakatan, Chief Executive Officer of the Company, certify, pursuant to 18
U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley
Act of 2002, that:

      (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 result of operations of the
Company.

                                    /s/Gerald J. Yakatan, Ph.D.
                                    ------------------------------------
                                    Gerald J. Yakatan, Ph.D.
                                    Chief Executive Officer

                                    August 13, 2004



A signed original of this written statement required by Section 906 of the
Sarbanes-Oxley Act of 2002 has been provided to AVANIR Pharmaceuticals and will
be retained by AVANIR Pharmaceuticals and furnished to the Securities and
Exchange Commission upon request.