<PAGE>
                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                                 F O R M 10-Q/A
                                (AMENDMENT NO. 1)

[X]      QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF
         THE SECURITIES EXCHANGE ACT OF 1934

         For the quarterly period ended July 5, 2003
                                        ------------

                                       OR


[ ]      TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
         EXCHANGE ACT OF 1934

         For the transition period from ______________ to _______________

                          Commission File Number 1-313
                                                 -----

                  T H E  L A M S O N  &  S E S S I O N S  C O.
                ------------------------------------------------
             (Exact name of Registrant as specified in its charter)

                   Ohio                                  34-0349210
----------------------------------------    -----------------------------------
      (State or other jurisdiction of         (IRS Employer Identification No.)
      incorporation or organization)

         25701 Science Park Drive
              Cleveland, Ohio                            44122-7313
----------------------------------------    -----------------------------------
(Address of principal executive offices)                 (Zip Code)

                                  216/464-3400
          ------------------------------------------------------------
              (Registrant's telephone number, including area code)


-------------------------------------------------------------------------------
   (Former name, former address and former fiscal year, if changed since last
                                    report.)

Indicate by check mark whether the Registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the Registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days.
Yes    X     No
    -------     -------

Indicate by check mark whether the Registrant is an accelerated filer (as
defined in Rule 12b-2 of the Exchange Act).
Yes            No    X
    ---------     --------

                       APPLICABLE ONLY TO ISSUERS INVOLVED
                        IN BANKRUPTCY PROCEEDINGS DURING
                            THE PRECEDING FIVE YEARS:

Indicate by check mark whether the Registrant has filed all documents and
reports required to be filed by Sections 12, 13 or 15(d) of the Securities
Exchange Act of 1934 subsequent to the distribution of securities under a plan
confirmed by a court.
Yes          No
    -------     -------

                      APPLICABLE ONLY TO CORPORATE ISSUERS:
As of July 5, 2003 the Registrant had outstanding 13,785,520 common shares.

<PAGE>
EXPLANATORY NOTE: The Lamson & Sessions Co.'s Quarterly Report on Form 10-Q
for the second quarter ended July 5, 2003 was due on or after August 14, 2003
and was filed on July 30, 2003. This Form 10-Q/A is being filed to include as
Exhibits 31 and 32 the certifications required by Sections 302 and 906 of the
Sarbanes-Oxley Act of 2002.



PART II
-------

ITEM 6 - EXHIBITS AND REPORTS ON FORM 8-K
-----------------------------------------


      (a)   Exhibits:

            31.1  Certification of John B. Schulze, Chief Executive Officer,
                  pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.

            31.2  Certification of James J. Abel, Chief Financial Officer,
                  pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.

            32.1  Certification of John B. Schulze, Chief Executive Officer,
                  pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.

            32.2  Certification of James J. Abel, Chief Financial Officer,
                  pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.





<PAGE>


                                   SIGNATURES
                                   ----------


      Pursuant to the requirements of the Securities Exchange Act of 1934, the
Registrant has duly caused this report to be signed on its behalf by the
undersigned, thereunto duly authorized.



                                     THE LAMSON & SESSIONS CO.
                                     -------------------------
                                             (Registrant)




July 30, 2003                        By: /s/ James J. Abel
                                        ----------------------------------
                                        James J. Abel
                                        Executive Vice President, Secretary,
                                        Treasurer and Chief Financial Officer