
                                                                    Exhibit 5




                               June 18, 1999



Board of Directors
GATX Corporation
500 West Monroe Street
Chicago, Illinois 60661

         Re:    GATX Corporation
                Registration Statement on Form S-8
                ----------------------------------

Ladies and Gentlemen:

         I have acted as counsel to GATX Corporation (the "Company"), in
connection with the adoption of an amendment (the "Amendment") to the GATX
Corporation 1995 Long Term Incentive Compensation Plan (as amended by the
Amendment, the "Plan"). I am familiar with the corporate proceedings
relative to the adoption of the Amendment and the proposed issuance of
2,000,000 additional shares of common stock, par value $.625 per share, of
the Company (the "Common Stock") pursuant to the Amendment. I have examined
such corporate and other records, instruments, certificates and documents
as I considered necessary to enable me to express this opinion.

         Based on the foregoing, it is my opinion that the additional
shares of Common Stock issuable pursuant to the Plan have been duly
authorized for issuance and, when sold pursuant to the Plan, will be
validly issued, fully paid, and non-assessable.

         I hereby consent to the filing of this opinion as an exhibit to
the Registration Statement on Form S-8 to be filed by the Company with
respect to the additional shares of Common Stock issuable pursuant to the
Plan and to the reference to me under the caption "Interests of Named
Experts and Counsel" in such Registration Statement.

                             Very truly yours,


                             /s/ Ronald J. Ciancio
                             ------------------------------
                             Ronald J. Ciancio
                             Assistant General Counsel



