EXHIBIT 23.1



                         CONSENT OF INDEPENDENT AUDITORS


We consent to the  incorporation  by  reference in the  Registration  Statements
(Form S-8 No.  33-37500  and No.  333-108321)  pertaining  to the  401(k)  Stock
Purchase Plan for Employees of  Cullen/Frost  Bankers,  Inc. and Its Affiliates,
the Registration Statement (Form S-8 No. 33-39478) pertaining to the 1991 Thrift
Incentive  Stock Purchase Plan for Employees of Cullen/Frost  Bankers,  Inc. and
Its Affiliates, the Registration Statement (Form S-8 No. 33-53492) pertaining to
the Cullen/Frost Bankers, Inc. Restricted Stock Plan, the Registration Statement
(Form S-8 No. 33-53622) pertaining to the Cullen/Frost  Bankers, Inc. 1992 Stock
Plan, the  Registration  Statement  (Form S-8 No.  333-68928)  pertaining to the
Cullen/Frost Bankers, Inc. 2001 Stock Plan, and the Registration Statement (Form
S-8 No.  333-102133)  pertaining to the 1997 Director Stock Plan of Cullen/Frost
Bankers,  Inc., of our report dated January 27, 2004,  except for Note 24, as to
which the date is February 13, 2004, with respect to the consolidated  financial
statements of Cullen/Frost  Bankers,  Inc.  included in this Annual Report (Form
10-K) for the year ended December 31, 2003.

                              /s/ Ernst & Young LLP

San Antonio, Texas
February 17, 2004