Exhibit 13.1


       Certification of the Principal Executive and Financial Officers of
                               CEMEX, S.A. de C.V.
                       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 Annual Report on Form 20-F of CEMEX, S.A. de C.V. (the
"Company") for the year ended December 31, 2005 as filed with the Securities and
Exchange Commission on the date hereof (the "Report"), Lorenzo H. Zambrano, as
Chief Executive Officer of the Company, and Hector Medina, as Executive Vice
President of Planning and Finance of the Company, each hereby certifies,
pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the
Sarbanes-Oxley Act of 2002, that, to the best of his 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.


/s/ Lorenzo H. Zambrano
-------------------------------------
Name:  Lorenzo H. Zambrano
Title: Chief Executive Officer
Date:  June 7, 2006


/s/ Hector Medina
-------------------------------------
Name:  Hector Medina
Title: Executive Vice President of
         Planning and Finance
Date:  June 7, 2006


This certification is furnished as an exhibit to the Report and accompanies the
Report pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 and shall not
be deemed filed by the Company for purposes of Section 18 of the Securities
Exchange Act of 1934, as amended.