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 Insituform Technologies, Inc. (the
"COMPANY") on Form 10-Q for the period ended September 30, 2003 as filed with
the Securities and Exchange Commission on the date hereof (the "FORM 10-Q"), I,
Thomas S. Rooney, Jr., President and Chief Executive Officer of the Company,
hereby certify, as of the date hereof, 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: November 14, 2003

                                          /s/ Thomas S. Rooney, Jr.
                                          -------------------------------------
                                          Thomas S. Rooney, Jr.
                                          President and Chief Executive Officer

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