Exhibit 31.2

                    CERTIFICATION OF CHIEF FINANCIAL OFFICER

In connection with the filing of the Quarterly Report on Form 10-Q for the
quarter ended September 30, 2004 by Kirby Corporation, Norman W. Nolen,
Executive Vice President, Treasurer and Chief Financial Officer, certifies that:

      1.    I have reviewed this quarterly report on Form 10-Q of Kirby
            Corporation (the "Company");

      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 Company as of, and for, the periods presented in
            this quarterly report;

      4.    The Company's other certifying officer 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
            Company and we 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 Company, 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 Company's disclosure
                  controls and procedures and presented in this quarterly report
                  our conclusions about the effectiveness of the disclosure
                  controls and procedures, as of the end of the period covered
                  by this quarterly report based on such evaluation; and

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

      5.    The Company's other certifying officer and I have disclosed, based
            on our most recent evaluation of internal control over financial
            reporting, to the Company's auditors and the audit committee of the
            Company's board of directors:

            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
                  Company'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
                  Company's internal controls over financial reporting.

                                                    /s/ NORMAN W. NOLEN
                                            -----------------------------------
                                                       Norman W. Nolen
                                            Executive Vice President, Treasurer
                                                 and Chief Financial Officer

Dated: November 8, 2004