Exhibit 5

                                March 31, 1999



Penton Media, Inc.
1100 Superior Avenue
Cleveland, Ohio  44114

      Re:  Penton Media, Inc. 1998 Equity and Performance Incentive Plan
           -------------------------------------------------------------

Ladies and Gentlemen:

          We have acted as counsel for Penton Media, Inc., a Delaware
corporation (the "Registrant"), in connection with the Penton Media, Inc. 1998
Equity and Performance Incentive Plan (the "Plan").  We have examined such
documents, records and matters of law as we have deemed necessary for the
purpose of this opinion, and based thereon, we are of the opinion that the
Registrant's shares of common stock, par value $.01 per share (the "Common
Stock"), that may be issued and sold pursuant to the Plan and the authorized
forms of agreement thereunder (the "Agreements") have been duly authorized and
will be, when issued and sold in accordance with the Plan and such Agreements,
validly issued, fully paid and nonassessable.

          We hereby consent to the filing of this opinion as Exhibit 5 to the
Registration Statement on Form S-8 filed by the Registrant to effect
registration of the Common Stock to be issued and sold pursuant to the Plan
under the Securities Act of 1933.

                                         Very truly yours,


                                         /s/  JONES, DAY, REAVIS & POGUE