EXHIBIT 32.1

                          CAPSTEAD MORTGAGE CORPORATION
                           CERTIFICATIONS 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 Capstead Mortgage Corporation (the
"Issuer") 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, Andrew
F. Jacobs, President and Chief Executive Officer of the Issuer, 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 results of
                  operations of the Issuer.

Date: August 7, 2003                   By: /s/ ANDREW F. JACOBS
                                           -------------------------------------
                                           Andrew F. Jacobs
                                           President and Chief Executive Officer

In connection with the Quarterly Report of Capstead Mortgage Corporation (the
"Issuer") 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, Phillip
A. Reinsch, Senior Vice President and Chief Financial Officer of the Issuer,
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 results of
                  operations of the Issuer.

Date: August 7, 2003                   By: /s/ PHILLIP A. REINSCH
                                           ------------------------------------
                                           Phillip A. Reinsch
                                           Senior Vice President and
                                           Chief Financial Officer