Exhibit 32.2

                            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 Encysive Pharmaceuticals Inc.
(the "Company") on Form 10-Q for the quarter ended September 30, 2004 (the
"Report"), as filed with the Securities and Exchange Commission on the date
hereof, I, Stephen L. Mueller, Vice President, Finance and Administration,
Secretary and Treasurer 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, as amended; and

            2. The information contained in the Report fairly presents, in all
material respects, the financial condition and results of operations of the
Company.

/s/  Stephen L. Mueller
- --------------------------------------
Stephen L. Mueller
Vice President, Finance and Administration
Secretary & Treasurer

November 4, 2004

A signed original of this written statement required by Section 906 has been
provided to Encysive Pharmaceuticals Inc. and will be retained by Encysive
Pharmaceuticals Inc. and furnished to the Securities and Exchange Commission or
its staff upon request.