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                [Keating, Muething & Klekamp, P.L.L. Letterhead]


                                                                       Exhibit 5

PAUL V. MUETHING
DIRECT DIAL: (513)579-6517
FACSIMILE: (513)579-6578
E-MAIL: PMUETHING@KMKLAW.COM


                                 April 13, 1999


American Financial Group, Inc.
One East Fourth Street
Cincinnati, Ohio   45202

Ladies and Gentlemen:

         We have acted as counsel to American Financial Group, Inc. (the
"Company") in connection with the Registration Statement on Form S-3
(Registration No. 333-21995) filed with the Securities and Exchange Commission
on February 18, 1997 and Post-Effective Amendment No. 1 to such Registration
Statement filed on December 5, 1997, as supplemented by the Prospectus
Supplement dated April 12, 1999 (Post-Effective Amendment No. 1 to such
registration statement as so supplemented is hereafter referred to as the
"Registration Statement") relating to the public offering of an aggregate
principal amount of $350,000,000 of its 7-1/8% Senior Debentures due 2009 (the
"Securities").

         In reaching the conclusions expressed herein, we have examined and
relied upon the original or copies, certified to our satisfaction, of (i) the
Amended and Restated Articles of Incorporation and the Code of Regulations of
the Company; (ii) copies of resolutions of the Board of Directors of the
Company, or committees thereof, authorizing the issuance of the Securities and
related matters; (iii) the Registration Statement and all exhibits thereto; and
(iv) such other documents and instruments as we have deemed necessary for the
expression of opinion herein contained. In making the foregoing examinations, we
have assumed the genuineness of all signatures and the authenticity of all
documents submitted to us as originals, and the conformity to original documents
of all documents submitted to us as certified or photostatic copies. As to
various questions of fact material to this opinion, we have relied, to the
extent we deem reasonably appropriate, upon representations or certificates of
officers or directors of the Company and upon documents, records and instruments
furnished to us by the Company, without independent check or verification of
their accuracy.

         Based on the foregoing, we are of the opinion that when, and if,
issued, delivered and paid 


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American Financial Group, Inc.
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April 13, 1999


for, the Securities will be duly authorized, validly issued and binding
obligations of the Company.

         We hereby consent to the reference to our firm under the caption "Legal
Matters" in the Registration Statement. In providing this consent, we do not
thereby admit that we are within the category of persons whose consent is
required under Section 7 of the Securities Act of 1933 or the rules and
regulations of the Commission promulgated thereunder.

                                  Yours truly,

                                  KEATING, MUETHING & KLEKAMP, P.L.L.



                                  By: /s/ Paul V. Muething                  
                                     ----------------------------------------
                                              Paul V. Muething