AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON AUGUST 27, 2004
                                                      REGISTRATION NO. 333-66714

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                             ----------------------

                         POST-EFFECTIVE AMENDMENT NO. 1
                                       TO
                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                             ----------------------

                          INSITUFORM TECHNOLOGIES, INC.
             (Exact name of registrant as specified in its charter)

            DELAWARE                                          13-3032158
 (State or other jurisdiction of                           (I.R.S. Employer
 incorporation or organization)                         Identification Number)

         702 SPIRIT 40 PARK DRIVE
          CHESTERFIELD, MISSOURI                             63005
 (Address of principal executive offices)                  (Zip Code)

                             ----------------------

                          INSITUFORM TECHNOLOGIES, INC.
                       2001 EMPLOYEE EQUITY INCENTIVE PLAN

                               CHRISTIAN G. FARMAN
                   VICE PRESIDENT AND CHIEF FINANCIAL OFFICER
                          INSITUFORM TECHNOLOGIES, INC.
                            702 SPIRIT 40 PARK DRIVE
                          CHESTERFIELD, MISSOURI 63005
                     (Name and address of agent for service)

   Telephone number, including area code, of agent for service: (636) 530-8000

                             ----------------------

                                    Copy to:
                             ROBERT M. LAROSE, ESQ.
                               THOMPSON COBURN LLP
                                ONE US BANK PLAZA
                            ST. LOUIS, MISSOURI 63101
                                 (314) 552-6000



                                              CALCULATION OF REGISTRATION FEE
========================= ================== ========================== ========================= =========================
                                                                                     
  Title of Securities       Amount to be         Proposed Maximum           Proposed Maximum       Amount of Registration
         to be               Registered         Offering Price Per         Aggregate Offering               Fee
       Registered                                    Share(3)                   Price(3)
------------------------- ------------------ -------------------------- ------------------------- -------------------------
 Class A common stock,        1,000,000               $17.75                  $17,750,000                $2,248.93
    $0.01 par value         shares(1)(2)
========================= ================== ========================== ========================= =========================


(1)    Includes one attached Preferred Stock Purchase Right per share.

(2)    Represents 1,000,000 shares added to the Insituform Technologies, Inc.
       2001 Employee Equity Incentive Plan, as amended. The amended plan was
       approved at the Company's 2003 annual meeting of stockholders held on May
       29, 2003.

(3)    Estimated solely for purposes of computing the Registration Fee pursuant
       to the provisions of Section 457(h), based upon the average of the high
       and low sale prices of Class A common stock, $0.01 par value, of the
       Registrant as reported on the Nasdaq National Market on August 26,
       2004.

                             ----------------------



         This Post-Effective Amendment No. 1 to the Registration Statement on
Form S-8 ("Registration Statement") incorporates by reference the contents and
information set forth in the Registration Statement on Form S-8 (File No.
333-66714) filed with the Securities and Exchange Commission on August 3, 2001,
pursuant to which the Registrant registered 1,000,000 shares of the Registrant's
common stock, $0.01 par value, under the Insituform Technologies, Inc. 2001
Employee Equity Incentive Plan ("Plan").

         On May 29, 2003, the shareholders of the Registrant approved an
amendment to the Plan increasing the total number of shares available under the
Plan from 1,000,000 shares to 2,000,000 shares. This Post-Effective Amendment
registers the additional 1,000,000 shares available under the Plan as a result
of this amendment.

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 8.  Exhibits.
         --------

         See the Exhibit Index attached hereto.





                                   SIGNATURES

         THE REGISTRANT. Pursuant to the requirements of the Securities Act of
1933, as amended, the Registrant certifies that it has reasonable grounds to
believe that it meets all of the requirements for filing on Form S-8 and has
duly caused this Amendment No. 1 to the Registration Statement to be signed on
its behalf by the undersigned, thereunto duly authorized, in the County of St.
Louis County, State of Missouri, on August 27, 2004.

                                 INSITUFORM TECHNOLOGIES, INC.



                                 By  /s/ Christian G. Farman
                                    ------------------------------------------
                                    Christian G. Farman
                                    Vice President and Chief Financial Officer


                                POWER OF ATTORNEY

         Each person whose signature appears below hereby constitutes and
appoints Christian G. Farman the undersigned's true and lawful attorney-in-fact
and agent, with full power of substitution and resubstitution, for the
undersigned and in the undersigned's name, place and stead, in any and all
capacities, to sign any and all amendments (including post-effective amendments)
to this Registration Statement on Form S-8 with respect to the 2001 Employee
Equity Incentive Plan, and to file the same, with exhibits and any and all other
documents filed with respect thereto, with the Securities and Exchange
Commission (or any other governmental or regulatory authority), granting unto
said attorney-in-fact and agent full power and authority to do and to perform
each and every act and thing requisite and necessary to be done in ratifying and
confirming all that said attorney-in-fact and agent or his substitute or
substitutes, may lawfully do or cause to be done by virtue hereof.

         Pursuant to the requirements of the Securities Act of 1933, as amended,
this Registration Statement has been signed by the following persons in the
capacities and on the date indicated.



SIGNATURE                                                TITLE                                  DATE
---------                                                -----                                  ----
                                                                                     

  /s/ Thomas S. Rooney, Jr.               President, Chief Executive Officer               August 27, 2004
------------------------------------                 and Director
Thomas S. Rooney, Jr.
Principal Executive Officer


  /s/ Christian G. Farman                 Vice President and Chief Financial               August 27, 2004
------------------------------------                    Officer
Christian G. Farman
Principal Financial and Accounting
Officer


  /s/ Robert W. Affholder                              Director                            August 27, 2004
-----------------------------------
Robert W. Affholder





SIGNATURE                                                TITLE                                  DATE
---------                                                -----                                  ----
                                                                                     

  /s/ Paul A. Biddelman                                Director                            August 27, 2004
------------------------------------
Paul A. Biddelman


  /s/ Stephen P. Cortinovis                            Director                            August 27, 2004
------------------------------------
Stephen P. Cortinovis


  /s/ John P. Dubinsky                                 Director                            August 27, 2004
------------------------------------
John P. Dubinsky


  /s/ Juanita H. Hinshaw                               Director                            August 27, 2004
------------------------------------
Juanita H. Hinshaw


  /s/ Thomas N. Kalishman                              Director                            August 27, 2004
------------------------------------
Thomas N. Kalishman


  /s/ Sheldon Weinig                                   Director                            August 27, 2004
------------------------------------
Sheldon Weinig


  /s/ Alfred L. Woods                                  Director                            August 27, 2004
------------------------------------
Alfred L. Woods




                                  EXHIBIT INDEX

  EXHIBIT NO.
  -----------

      4.1         Restated Certificate of Incorporation, as amended, of the
                  Company (incorporated by reference to Exhibit 3.1 to the
                  quarterly report on Form 10-Q for the quarter ended June 30,
                  2000), and Certificate of Designation, Preferences and Rights
                  of Series A Junior Participating Preferred Stock (incorporated
                  by reference to Exhibit 3.1 to the annual report on Form 10-K
                  for the year ended December 31, 2001).

      4.2         By-Laws, as amended, of the Company (incorporated herein by
                  reference to Exhibit 3.1 to the Company's Quarterly Report on
                  Form 10-Q for the quarter ended June 30, 2003).

      4.3         Rights Agreement dated as of February 26, 2002 between the
                  Company and American Stock Transfer & Trust Company
                  (incorporated by reference to Exhibit 1 to the Registration
                  Statement on Form 8-A dated March 8, 2002).

      5.1         Opinion of Thompson Coburn LLP as to the legality of the
                  securities being registered.

      23.1        Consent of PricewaterhouseCoopers LLP.

      23.2        Consent of Arthur Andersen LLP*

      23.3        Consent of Thompson Coburn LLP (included in Exhibit 5.1).

      24.1        Power of Attorney (set forth on signature page hereto).

      99.1        Amended and Restated 2001 Employee Equity Incentive Plan
                  (incorporated by reference to Appendix C to the definitive
                  proxy statement on Schedule 14A filed on April 16, 2003 in
                  connection with the 2003 annual meeting of stockholders).

---------------
* A currently dated consent from Arthur Andersen LLP has been omitted in
reliance on Rule 437a under the Securities Act of 1933. Because Arthur Andersen
LLP has ceased operations and has not consented to the incorporation by
reference of its report for the year ended December 31, 2001, the ability of
purchasers of securities sold hereunder to seek potential recoveries from Arthur
Andersen LLP related to any claims that they may assert as a result of the audit
performed by Arthur Andersen LLP will be limited significantly.