<PAGE>

                                                                    Exhibit 31.1

Certificate pursuant to Rule 13a-14(a) or 15d-14(a) of Securities Exchange Act
of 1934 as adopted pursuant to section 302 of Sarbanes-Oxley Act of
2002-Principle Executive Officer

I, William A. Hines, certify that:

    1.  I have reviewed this Form 10-Q of UNIFAB International, Inc.;

    2.  Based on my knowledge, this 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 report;

    3.  Based on my knowledge, the financial statements, and other financial
        information included in this 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 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)) and internal
        control over financial reporting (as defined in Exchange Act Rules
        13a-15(f) and 15d-15(f)) 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 report is being prepared;

        (b) Designed such internal control over financial reporting, or caused
            such internal control over financial reporting to be designed under
            our supervision, to provide reasonable assurance regarding the
            reliability of financial reporting and the preparation of financial
            statements for external purposes in accordance with generally
            accepted accounting principles;

        (c) 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

        (d) 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 (the registrant's fourth
            fiscal quarter in the case of an annual report) 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 the
        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: November 12, 2003

/s/ William A. Hines
---------------------------
William A. Hines
Principle Executive Officer



                                       23