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 on Form 10-Q of Insituform Technologies,
Inc. (the "COMPANY") for the quarter ended March 31, 2005 as filed with the
Securities and Exchange Commission on the date hereof (the "FORM 10-Q"), I,
Christian G. Farman, Senior Vice President and Chief Financial Officer of the
Company, hereby certify as of the date hereof, pursuant to 18 U.S.C. Section
1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002,
that:

            (1)   the Form 10-Q fully complies with the requirements of section
                  13(a) or 15(d) of the Securities Exchange Act of 1934; and

            (2)   information contained in the Form 10-Q fairly presents, in all
                  material respects, the financial condition and results of
                  operations of the Company.

Dated: May 10, 2005
                               /s/ Christian G. Farman
                               -------------------------------------------------
                               Christian G. Farman
                               Senior Vice President and Chief Financial Officer