<PAGE>

                                                                     Exhibit 4.3



                               PENTON MEDIA, INC.
                         MANAGEMENT STOCK PURCHASE PLAN
           (As Amended and Restated Effective as of January 1, 2000)

                                   ARTICLE I

                              Purpose of the Plan

     The purpose of the Penton Media, Inc. Management Stock Purchase Plan (As
Amended and Restated Effective as of January 1, 2000) (the "Plan") is to provide
a means for designated officers and other key employees of Penton Media, Inc.
(the "Company") and its Subsidiaries to acquire a proprietary interest (or
increase an existing interest) in the Company.  Participants in the Plan may
elect to receive restricted stock units ("RSUs") in lieu of a designated portion
of up to one hundred percent (100%) of their annual incentive bonus ("Bonus")
under the Penton Media, Inc. Senior Executive Bonus Plan or other similar
arrangement (the "Bonus Plan").  Each RSU represents the right to receive one
share of the common stock, par value $.01 of the Company (the "Common Stock")
upon the terms and conditions stated herein.  RSUs are granted at a discount of
20% of the Fair Market Value (as defined in Section 4.2 of the Plan) on the date
the RSUs are awarded.  So long as the participant remains employed by Company
for at least two years after the date of grant or until the occurrence of
certain specified events, his or her RSUs will be settled in shares of Common
Stock after a period of deferral selected by the participant, or upon
termination of employment, if earlier.

                                   ARTICLE II

                                 Administration

     The Plan shall be administered by the Compensation Committee (the
"Committee") of the Board of Directors of the Company (the "Board").  The
Committee shall have complete discretion and authority with respect to the Plan
and its application, except as expressly limited herein.  Determinations by the
Committee shall be final and binding on all parties with respect to all matters
relating to the Plan.

                                  ARTICLE III

                                  Eligibility

     Officers and other key employees of the Company and its Subsidiaries as
designated by the Committee shall be eligible to participate in the Plan.  For
all purposes of the Plan, the term "Subsidiary" means any corporation or other
legal entity in which the Company owns, directly or indirectly, an equity
interest.

                                   ARTICLE IV

                                 Participation

     4.1  Generally.  Participation in the Plan shall be based on the award of
RSUs.  Each RSU awarded to a participant shall be credited to a bookkeeping
account established and maintained for that participant.

     4.2  Price of RSUs.  The "Price" of each RSU shall be equal to eighty
percent (80%) of the Fair Market Value on the date the RSU is awarded.  For all
purposes of the Plan, the "Fair Market Value" on any given date shall mean the
average of the high and low sales price of a share of Common Stock on the New
York Stock Exchange or other public exchange on which the Common Stock is traded
on such date or, if the Common Stock is not publicly traded on such date, the
value of the Common Stock as determined by the Committee.
<PAGE>

     4.3  Election to Participate.  No later than March 31 of any year, each
participant may elect to receive RSUs in lieu of all or a specified part of his
or her Bonus that may become payable to him or her for performance in such year
under the Bonus Plan that in the absence of such election would be payable in
the following year; provided, however, that, with respect to any Bonus payable
in 2000, a participant may make an election on or prior to September 10, 1999.
Such election shall be made on an election form specified by the Committee (an
"Election Form") and filed with the Committee. An Election Form that is timely
delivered shall be effective for the Bonus earned in the relevant calendar year
(or, with respect to any Bonus payable in 2000, earned in 1999).  Such election
may be expressed as a specified percentage (up to one hundred percent (100%)) of
the participant's actual Bonus amount or a specified dollar amount (up to one
hundred percent (100%)) of the participant's Bonus.  Any percentage amount
specified must be at least 10% of the Bonus otherwise payable.  Any dollar
amount specified must be at least $5,000.  Amounts specified are entirely
contingent on the amount of Bonus actually awarded.

     4.4  Deferral Period.  Each Election Form shall specify a deferral period
for the RSUs to which it pertains (the "Deferral Period").  The Deferral Period
shall be expressed as a number of whole years, not less than two, beginning on
the award date.  Subject to the approval of the Company as described below in
this Section, a participant may make a subsequent election requesting a change
in the Deferral Period (subject to the limitations set forth in this Section).
Such subsequent election shall be on a form provided by the Company, which form
must be filed with the Company (a) at a time at which the participant is an
employee of the Company or a Subsidiary and (b), except as described below in
the sentence that immediately follows, at least one (1) year prior to the date
on which the participant otherwise would be entitled to receive shares of Common
Stock.  The one (1) year notice requirement described above, however, does not
apply in the case where the participant otherwise would be entitled to receive
shares of Common Stock following an involuntary termination of the participant's
employment, including by reason of death or permanent disability.

     4.5  Awards.  Once each year, on the date that Bonuses are paid or would
otherwise be paid, the Company shall award RSUs to each participant as follows:
Each participant's account shall be credited with a whole number of RSUs
determined by dividing the amount (expressed in dollars) that is determined
under his or her Election Form by the Price of each RSU awarded on such date.
No fractional RSU will be credited and the amount equivalent in value to the
fractional RSU will be paid out to the participant currently in cash.

                                   ARTICLE V

                             Vesting and Settlement

     5.1  Normal Vesting.  A participant shall be fully vested in each RSU on
the second anniversary of the date of award of the RSU.

     5.2  Accelerated Vesting.  Notwithstanding Section 5.1 of the Plan, a
participant's RSUs shall immediately become completely vested upon the
participant's death or permanent disability or upon a Change of Control (as
defined in Section 5.5 of the Plan).

     5.3  Settlement After Vesting.  With respect to each vested RSU, the
Company shall issue to the participant one share of Common Stock as soon as
practicable after the end of the Deferral Period specified in the participant's
Election Form pertaining to such RSU, or, if earlier, (a) upon the participant's
termination of employment in accordance with the provisions of Section 5.4 of
the Plan, or (b) the termination of the Plan.

     5.4  Settlement Prior to Vesting.

          (a) If a participant voluntarily terminates his or her employment with
     the Company, or the participant is terminated for Cause (as defined in
     Subsection 5.4(d) of the Plan), the participant's nonvested RSUs shall be
     canceled and he or she shall receive a cash payment equal to the lesser of
     (i) the Price of such RSUs or (ii) an amount equal to the number of such
     RSUs multiplied by the Fair Market Value on the date of the participant's
     termination of employment.

          (b) If a participant's employment is terminated by the Company for any
     reason other than Cause, the participant's nonvested RSUs shall be canceled
     and he or she shall receive payment as follows:  The number of nonvested
     RSUs awarded with respect to each award date shall be multiplied by a
     fraction that is equal to the
<PAGE>

     number of full months that the participant was employed by the Company
     after each such award date divided by twenty-four (24) and the participant
     shall receive the resulting number of such RSUs in shares of Common Stock
     (with any fractional shares resulting from such calculation being settled
     in cash). With respect to the participant's remaining nonvested RSUs, the
     participant shall receive cash in an amount equal to the lesser of (a) the
     Price of such RSUs or (b) an amount equal to the number of such RSUs
     multiplied by the Fair Market Value on the date of the participant's
     termination of employment.

          (c)  The Committee shall have complete discretion to determine the
     circumstances of a participant's termination of employment, including
     whether the same results from voluntary termination, permanent disability,
     termination for Cause, or termination by the Company for any reason other
     than Cause.  The Committee's determination shall be final and binding on
     all parties and not subject to review or challenge by any participant or
     other person.

          (d)  For purposes of the Plan, "Cause" shall mean:

               (i)    the commission by the participant of a felony or a crime
                      involving moral turpitude;

               (ii)   the commission by the participant of a fraud;

               (iii)  the commission by the participant of any act involving
                      dishonesty or disloyalty with respect to the Company or
                      any of its Subsidiaries or affiliates that harms or
                      damages any of them to any extent;

               (iv)   conduct by the participant that brings the Company or
                      any of its Subsidiaries or affiliates into substantial
                      public disgrace or disrepute; or

               (v)    gross negligence or willful misconduct by the participant
                      with respect to the Company or any of its Subsidiaries
                      or affiliates.

     5.5  Change of Control.  For purposes of the Plan, "Change of Control"
shall mean the occurrence of any of the following events:

          (a)  The acquisition by any individual, entity or group (within the
     meaning of Section 13(d)(3) or 14(d)(2) of the Securities Exchange Act of
     1934, as amended (the "Exchange Act")) (a "Person") of beneficial ownership
     (within the meaning of Rule 13d-3 promulgated under the Exchange Act) of
     40% or more of  either: (i) the then-outstanding shares of Common Stock or
     (ii) the combined voting power of the then-outstanding voting securities of
     the Company entitled to vote generally in the election of directors
     ("Voting Stock"); provided, however, that for purposes of this Subsection
                       --------- -------
     5.4(a), the following acquisitions shall not constitute a Change of
     Control: (A) any acquisition directly from the Company, (B) any acquisition
     by the Company, a Subsidiary or the Harris Group (as defined in Section 5.6
     of the Plan), (C) any acquisition by any employee benefit plan (or related
     trust) sponsored or maintained by the Company or any Subsidiary, or (D) any
     acquisition by any Person pursuant to a transaction which complies with
     clauses (i), (ii) and (iii) of Subsection 5.5(c); or

          (b)  Individuals who, as of the date hereof, constitute the Board (the
     "Incumbent Board") cease for any reason (other than death or permanent
     disability) to constitute at least a majority of the Board; provided,
                                                                 ---------
     however, that any individual becoming a director subsequent to the date
     -------
     hereof whose election, or nomination for election by the Company's
     shareholders, was approved by a vote of at least a majority of the
     directors then comprising the Incumbent Board (either by a specific vote or
     by approval of the proxy statement of the Company in which such person is
     named as a nominee for director, without objection to such nomination)
     shall be considered as though such individual were a member of the
     Incumbent Board, but excluding for this purpose, any such individual whose
     initial assumption of office occurs as a result of an actual or threatened
     election contest (within the meaning of Rule 14a-11 of the Exchange Act)
     with respect to the election or removal of directors or other actual or
     threatened solicitation of proxies or consents by or on behalf of a Person
     other than the Board; or

          (c)  Consummation of a reorganization, merger or consolidation or sale
     or other disposition of all or substantially all of the assets of the
     Company (a "Business Combination"), in each case, unless, following such
<PAGE>

     Business Combination, (i) all or substantially all of the individuals and
     entities who were the beneficial owners, respectively, of the Common Stock
     and Voting Stock immediately prior to such Business Combination
     beneficially own, directly or indirectly, more than a majority of,
     respectively, the then-outstanding shares of common stock and the combined
     voting power of the then-outstanding voting securities entitled to vote
     generally in the election of directors, as the case may be, of the entity
     resulting from such Business Combination (including, without limitation, an
     entity which as a result of such transaction owns the Company or all or
     substantially all of the Company's assets either directly or through one or
     more Subsidiaries) in substantially the same proportions relative to each
     other as their ownership, immediately prior to such Business Combination,
     of the Common Stock and Voting Stock of the Company, as the case may be,
     (ii) no Person (excluding any entity resulting from such Business
     Combination, the Harris Group or any employee benefit plan (or related
     trust) sponsored or maintained by the Company, a Subsidiary or such entity
     resulting from such Business Combination) beneficially owns, directly or
     indirectly, 40% or more of, respectively, the then-outstanding shares of
     common stock of the entity resulting from such Business Combination, or the
     combined voting power of the then-outstanding voting securities of such
     corporation, except to the extent that such ownership existed prior to the
     Business Combination and (iii) at least a majority of the members of the
     board of directors of the corporation resulting from such Business
     Combination were members of the Incumbent Board at the time of the
     execution of the initial agreement, or of the action of the Board providing
     for such Business Combination; or

          (d)  Approval by the shareholders of the Company of a complete
     liquidation or dissolution of the Company.

     5.6  Harris Group.  For purposes of Section 5.5 of the Plan, the "Harris
Group" shall mean Messrs. Irving B. Harris, Neison Harris, King Harris, William
W. Harris and June H. Barrows, and their respective spouses, descendants and
spouses of descendants, trustees of trusts established for the benefit of such
persons (acting in their capacity as trustees of such trusts), and executors of
estates of such persons (acting in their capacity as executors of such estates),
and each entity of which any of the foregoing owns (a) more than fifty percent
(50%) of the voting stock or other voting interests and (b) stock or other
interests representing more than fifty percent (50%) of the total value of the
stock or other interests of such entity.

                                   ARTICLE VI

                          Dividend Equivalent Amounts

     Whenever dividends (other than dividends payable only in shares of stock)
are paid with respect to Common Stock, each participant shall be paid an amount
in cash equal to the number of his or her vested RSUs multiplied by the dividend
value per share.  In addition, each participant's account shall be credited with
an amount equal to the number of such participant's nonvested RSUs multiplied by
the dividend value per share.  Amounts credited with respect to each nonvested
RSU shall be paid, without interest, on the earlier of the date the participant
becomes vested in such RSU, or when the participant receives payment for his or
her nonvested RSUs pursuant to Section 5.4 of the Plan.

                                  ARTICLE VII

                           Designation of Beneficiary

     Upon the death of a participant, his or her account shall be paid to the
beneficiary or beneficiaries designated by him or her.  If there is no
designated beneficiary, or no designated beneficiary surviving at a
participant's death, payment of a participant's account shall be made to his or
her estate.  Beneficiary designations shall be made in writing.  A participant
may designate a new beneficiary or beneficiaries at any time by notifying the
Committee.

                                  ARTICLE VIII

                        Shares Available Under the Plan

     The aggregate maximum number of shares of Common Stock reserved and
available for issuance under the Plan shall be 250,000 shares of Common Stock.
For purposes of this limitation, the shares of Common Stock underlying any RSUs
that are canceled shall be added back to the shares of Common Stock available
for issuance under the Plan.  Such shares may be shares of original issuance or
treasury shares or a combination of the foregoing.
<PAGE>

                                  ARTICLE IX

                                  Adjustments

     The Committee may make or provide for such adjustments in the numbers of
shares of Common Stock covered by outstanding RSUs granted hereunder, in the
Price of each RSU, and in the kind of shares covered thereby, as the Committee,
in its sole discretion, exercised in good faith, may determine is equitably
required to prevent dilution or enlargement of the rights of participants that
otherwise would result from (a) any stock dividend, stock split, combination of
shares, recapitalization or other change in the capital structure of the
Company, or (b) any merger, consolidation, spin-off, split-off, spin-out, split-
up, reorganization, partial or complete liquidation or other distribution of
assets, issuance of rights or warrants to purchase securities, or (c) any other
corporate transaction or event having an effect similar to any of the foregoing.
Moreover, in the event of any such transaction or event, the Committee, in its
discretion, may provide in substitution for any or all outstanding awards under
the Plan such alternative consideration as it, in good faith, may determine to
be equitable in the circumstances and may require in connection therewith the
surrender of all awards so replaced.  The Committee may also make or provide for
such adjustments in the numbers of shares specified in Article VIII of the Plan
as the Committee in its sole discretion, exercised in good faith, may determine
is appropriate to reflect any transaction or event described in this Article IX.

                                   ARTICLE X

                      Amendment or Termination of the Plan

     The Company reserves the right to amend or terminate the Plan at any time,
by action of its Board, provided that no such action shall adversely affect a
participant's rights under the Plan with respect to RSUs awarded before the date
of such action.

                                   ARTICLE XI

                            Miscellaneous Provisions

     11.1 Taxes.  To the extent that the Company is required to withhold
Federal, state or local taxes in connection with any component of a
participant's compensation in cash or shares of Common Stock, and the amounts
available to the Company for such withholding are insufficient, it shall be a
condition to the receipt of any shares of Common Stock that the participant make
arrangements satisfactory to the Company for the payment of the balance of such
taxes required to be withheld, which arrangement may include relinquishment of
the shares of Common Stock.  The Company and a participant may also make similar
arrangements with respect to payment of any other taxes derived from or related
to the payment of shares of Common Stock with the respect to which withholding
is not required.

     11.2 Hardship Distributions.  Prior to the time a participant's account
becomes payable, the Committee, in its sole discretion, may elect to distribute
all or a portion of any vested RSUs in the participant's account in the event
such participant requests a distribution on account of severe financial
hardship.  For purposes of this Plan, severe financial hardship shall be deemed
to exist in the event the Committee determines that a participant needs a
distribution to meet immediate and heavy financial needs resulting from a sudden
or unexpected illness or accident of the participant or a member of his or her
family, loss of the participant's property due to casualty, or other similar
extraordinary and unforeseeable circumstances arising as a result of events
beyond the control of the participant.  A  distribution based on financial
hardship shall not exceed the amount required to meet the immediate financial
need created by the hardship.

     11.3 Assignment.  No right or interest of any participant (or any person
claiming through or under such participant, other than the surviving spouse of
such participant after the participant is deceased) in any benefit or payment
herefrom shall be assignable or transferable in any manner or be subject to
alienation, anticipation, sale, pledge, encumbrance or other legal process or in
any manner be liable for or subject to the debts or liabilities of such
participant.  If any participant or any such person (other than the surviving
spouse of such participant after the participant is deceased) shall attempt to
or shall transfer, assign, alienate, anticipate, sell, pledge or otherwise
encumber his or her benefits hereunder or any part thereof, or if by reason of
his or her bankruptcy or other event happening at any time such benefits would
devolve upon anyone else or would not be enjoyed by him or her, then the
Committee, in its discretion, may terminate his or her interest in any such
benefit to the extent the Committee considers necessary or advisable to prevent
<PAGE>

or limit the effects of such occurrence.  Termination shall be effected by
filing a written "termination declaration" with the Committee records and making
reasonable efforts to deliver a copy to such participant or other person or his
or her legal representative.

     As long as any individual whose interests hereunder are subject to a
termination declaration is alive, any benefits affected by the termination shall
be retained by the Company and, in the Committee's sole and absolute judgment,
may be paid to or expended for the benefit of such individual, his or her
spouse, his or her children or any other person or persons in fact dependent
upon him or her in such a manner as the Committee shall deem proper.  Upon the
death of any individual, all benefits withheld from him or her and not paid to
others in accordance with the preceding sentence shall be distributed to such
individual's estate or to his or her creditors and if such individual shall have
descendants, including adopted children, then living, distribution shall be made
to such individual's then living descendants, including adopted children, per
stirpes.

     11.4 Unfunded and Unsecured.  The Plan shall at all times be entirely
unfunded, and no provision shall at any time be made with respect to segregating
assets of the Company (including Common Stock) for payment of any amounts or
issuance of any shares of Common Stock hereunder.  No participant or other
person shall have any interest in any particular assets of the Company
(including Common Stock) by reason of the right to receive payment under the
Plan, and any participant or other person shall have only the rights of a
general unsecured creditor of the Company with respect to any rights under the
Plan.

     11.5 Governing Law.  The terms of the Plan shall be governed construed,
administered and regulated in accordance with the laws of the State of Ohio.

     11.6 Effective Date.  The Plan shall become effective as of August 26,
1999.