EXHIBIT 31(a)

                            SECTION 302 CERTIFICATION

        I, James L. Simonton, certify that:

        1. I have reviewed this Amendment No. 1 to Form 10-Q for the period
ended September 30, 2003 of Core Molding Technologies, Inc.;

        2. Based on my knowledge, this quarterly report does not contain any
untrue statement of a material fact or omit to state a material fact necessary
to make the statements made, in light of the circumstances under which such
statements were made, not misleading with respect to the period covered by this
quarterly report;

        3. Based on my knowledge, the financial statements, and other financial
information included in this quarterly report, fairly present in all material
respects the financial condition, results of operations and cash flows of the
registrant as of, and for, the periods presented in this quarterly report;

        4. The registrant's other certifying officer(s) and I are responsible
for establishing and maintaining disclosure controls and procedures (as defined
in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the registrant and have:

        a)      Designed such disclosure controls and procedures, or caused such
                disclosure controls and procedures to be designed under our
                supervision, to ensure that material information relating to the
                registrant, including its consolidated subsidiaries, is made
                known to us by others within those entities, particularly during
                the period in which this quarterly report is being prepared;

        b)      Evaluated the effectiveness of the registrant's disclosure
                controls and procedures and presented in this report our
                conclusions about the effectiveness of the disclosure controls
                and procedures, as of the end of the period covered by this
                report based on such evaluation; and

        c)      Disclosed in this report any change in the registrant's internal
                control over financial reporting that occurred during the
                registrant's most recent fiscal quarter that has materially
                affected, or is reasonably likely to materially affect, the
                registrant's internal control over financial reporting; and

        5. The registrant's other certifying officer(s) and I have disclosed,
based on our most recent evaluation of internal control over financial
reporting, to the registrant's auditors and the audit committee of registrant's
board of directors (or persons performing the equivalent functions):

        a)      All significant deficiencies and material weaknesses in the
                design or operation of internal control over financial reporting
                which are reasonably likely to adversely affect the registrant's
                ability to record, process, summarize and report financial
                information; and


        b)      Any fraud, whether or not material, that involves management or
                other employees who have a significant role in the registrant's
                internal control over financial reporting.



Date: December 22, 2003

                                /s/ James L. Simonton
                               --------------------------------------------
                               James L. Simonton
                               President, Chief Executive Officer and Director


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