EXHIBIT 4.5

         SECOND AMENDMENT TO CULLEN/FROST BANKERS, INC. 1992 STOCK PLAN


         The Board of Directors of Cullen/Frost Bankers, Inc. (the "Company"),
pursuant to Section 9.5 of the Cullen/Frost Bankers, Inc. 1992 Stock Plan (the
"Plan"), hereby amends the Plan as described below; provided, however, that such
amendments shall become effective only after approval by the Company's
shareholders. The amendments are as follows:

The First Paragraph of Section 5.1 of the Plan shall be deleted and replaced
with the following:

5.1.     NUMBER OF SHARES AVAILABLE FOR GRANT. Subject to adjustment as provided
         in Section 5.2 herein, the number of Shares hereby reserved for
         issuance to Participants under the Plan shall be four million five
         hundred sixty thousand (4,560,000). In no event may greater than four
         hundred sixty-five thousand (465,000) shares be available for issuance
         with respect to grants of Restricted Stock under the Plan. The Board
         shall determine the appropriate methodology for calculating the number
         of shares issued pursuant to the Plan. Unless and until the Board
         determines that an Incentive granted to a Covered Employee shall not be
         designed to comply with the Performance-Based Exception, the following
         rules apply to grants of such Incentives under the Plan:

Section 5.1(d) shall be added to the Plan and shall read as follows:

         (d)  Restricted Stock Units: The maximum aggregate grant with respect
              to Incentives granted in the form of Restricted Stock Unit granted
              in any one fiscal year to any one Participant shall be one hundred
              fifty thousand (150,000) shares of Common Stock.

Section 6 of the Plan is deleted in its entirety and replaced with the
following:

SECTION 6. RESTRICTED STOCK AND RESTRICTED STOCK UNITS

6.1.     GRANT OF RESTRICTED STOCK OR RESTRICTED STOCK UNITS. The Committee may,
         in its discretion, grant Incentives to Participants from time to time
         in the form of Restricted Stock or Restricted Stock Units and shall
         determine the number of shares or units of Restricted Stock that will
         be granted to a Participant.

6.2.     RESTRICTED STOCK AGREEMENT. Each grant of shares or units of Restricted
         Stock shall be evidenced by a Restricted Stock Agreement and shall be
         subject to the following terms and conditions and such other terms and
         conditions as the Committee may prescribe.


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6.3.     RESTRICTION PERIOD. At the time of the grant of shares or units of
         Restricted Stock, the Committee shall select the Restriction Period to
         apply to the shares or units of Restricted Stock.

6.4.     NONTRANSFERABILITY OF RESTRICTED STOCK. Prior to the lapse of
         restrictions as provided in Section 6.5, shares or units of Restricted
         Stock may not be sold, exchanged, transferred, pledged, assigned, or
         otherwise alienated, hypothecated, whether voluntarily or
         involuntarily.

6.5.     REMOVAL OF RESTRICTIONS. Except as otherwise provided in Section 6.9,
         and subject to Section 6.6, shares or units of Restricted Stock covered
         by each Restricted Stock grant made under this Plan shall become freely
         transferable by the Participant after the expiration of the Restriction
         Period or upon satisfaction of other conditions as specified by the
         Committee in its sole discretion.

6.6.     OTHER RESTRICTIONS. The Company shall impose such other restrictions on
         any shares or units granted pursuant to this Plan as it may deem
         advisable including, without limitation, restrictions under applicable
         Federal laws, under the requirements of any stock exchange or
         interdealer quotation system upon which share or shares of the same
         class are then listed or quoted and under blue sky or state securities
         laws applicable to such shares. The Company may legend the certificates
         representing Restricted Stock to give appropriate notice of such
         restrictions.

6.7.     CERTIFICATE LEGEND. In addition to any legends placed on certificates
         pursuant to Section 6.6 hereof, each certificate representing shares of
         Restricted Stock granted pursuant to the Plan shall bear the following
         legend: The sale or other transfer of the shares of stock represented
         by this certificate, whether voluntary, involuntary, or by operation of
         law, is subject to certain restrictions on transfer set forth in the
         Cullen/Frost Bankers, Inc. 1992 Stock Plan, and a Restricted Stock
         Agreement dated            . A copy of the Plan, such rules, and the
         Restricted Stock Agreement may be obtained from the Secretary of
         Cullen/Frost Bankers, Inc.

6.8.     VOTING RIGHTS AND DIVIDENDS WITH RESPECT TO RESTRICTED STOCK. With
         respect to shares of Restricted Stock, prior to the lapse of
         restrictions under Section 6.5, each Participant shall generally have
         the rights and privileges of a shareholder, including the right to vote
         the shares and to receive dividends and other distributions made with
         respect to the shares; provided, however, that the shares of Restricted
         Stock shall be subject to all the terms, conditions, and restrictions
         of the Plan and the Restricted Stock Agreement, including, without
         limitation, the provisions of this Section 6. Holders of Restricted
         Stock Units shall have no rights as to


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         voting or dividends prior to the lapse of restrictions under Section
         6.5, except as provided in the Restricted Stock Agreement.

6.9.     CHANGE IN CONTROL. In the event of a Change in Control, the applicable
         Restriction Period with respect to all outstanding shares or units of
         Restricted Stock shall automatically terminate.

A New Section 7.3(a) shall be added to the Plan as follows:

         (a)  Repricing of Stock Options. The purchase price of Stock issued
              under each Stock Option shall not be repriced without prior
              shareholder approval.

A New Section 9.7 shall be added to the Plan as follows:

9.7.     LIMITED TRANSFERABILITY. Each Incentive, and each right under any
         Incentive, shall be exercisable only by the Participant during the
         Participant's lifetime, or, if permissible under applicable law, by the
         Participant's guardian or legal representative as determined by the
         Committee; provided, however, that Incentives under the Plan may be
         transferred to immediate family members or family trusts as determined
         by the Committee.