**EXHIBIT 15**

**Exhibit 15 – Letter Re: Unaudited Interim Financial Information**

Board ofDirectors 

AmSouth Bancorporation 

We are aware of the incorporation by reference in the following Registration Statements and in their related Prospectuses, of our report dated August 4, 2006, relating to the unaudited consolidated financial statements of AmSouthBancorporation and subsidiaries that are included in its Form 10-Q for the quarter ended June 30, 2006: 

Form S-3No. 33-55683 pertaining to the AmSouth Bancorporation Dividend Reinvestment and Common Stock Purchase Plan; 

Form S-8No. 33-52113 pertaining to the AmSouth Bancorporation 1989 Long Term Incentive Compensation Plan; 

Form S-8No. 33-35218 pertaining to the AmSouth Bancorporation 1989 Long Term Incentive Compensation Plan; 

Form S-3No. 33-35280 pertaining to the AmSouth Bancorporation Dividend Reinvestment and Common Stock Purchase Plan; 

Form S-8No. 333-05631 pertaining to the AmSouth Bancorporation 1996 Long Term Incentive Compensation Plan; 

Form S-8No. 333-41599 pertaining to the AmSouth Bancorporation Deferred Compensation Plan and the Amended and Restated Deferred Compensation Plan for Directors of AmSouth Bancorporation; 

Form S-3 No. 333-44263 pertaining to the AmSouth Bancorporation Shelf Registration Statement; 

Form S-8 No. 333-76283 pertaining to the AmSouth Bancorporation Stock Option Plan for Outside Directors; 

Form S-8 No. 333-89451 pertaining to the First American Corporation 1993 Non-Employee Director Stock Option Plan; 

Form S-8 No. 333-89455 pertaining to the First American Corporation 1999 Broad-Based Employee Stock Option Plan; 

Form S-8 No. 333-89459 pertaining to the Deposit Guaranty Corporation Long Term Incentive Plans; 

Form S-8 No. 333-89461 pertaining to the First American Corporation 1991 Employee Stock Incentive Plan; 

Form S-8 No. 333-89463 pertaining to the Heritage Federal Bancshares, Inc. 1994 Stock Option Plan for Non-Employee Directors and1992 Stock Option Plan and Incentive Compensation Plan for Non-Employee Directors; 

Form S-3 No. 333-42542 pertainingto the AmSouth Bancorporation Dividend Reinvestment and Common Stock Purchase Plan; 

Form S-8 No. 333-42554 pertainingto the AmSouth Bancorporation Thrift Plan; 

Form S-8 No. 333-42556 pertaining to the AmSouth Bancorporation EmployeeStock Purchase Plan; 

Form S-8 No. 333-42558 pertaining to the AmSouth Bancorporation Amended and Restated 1991Employee Stock Incentive Plan; 

Form S-8 No. 333-42560 pertaining to the Pioneer Bancshares, Inc. Long-Term IncentivePlan; 

Form S-8 No. 333-102581 pertaining to the AmSouth Bancorporation Stock Option Plan for Outside Directors;

Form S-8 No. 333-102586 pertaining to the AmSouth Bancorporation 1996 Long Term Incentive Compensation Plan;

Form S-3 No. 333-42542 (as amended) pertaining to the AmSouth Bancorporation Direct Stock Purchase and DividendReinvestment Plan 

Form S-8 No. 333-118080 pertaining to the AmSouth Bancorporation 1996 Long Term IncentiveCompensation Plan; 

Form S-8 No. 333-118078 pertaining to the AmSouth Bancorporation Stock Option Plan for OutsideDirectors; 

Form S-8 No. 333-118079 pertaining to the AmSouth Bancorporation Employee Stock Purchase Plan; 

Form S-8 No. 333-133000 pertaining to the AmSouth Bancorporation Thrift Plan; and 

Form S-8 No. 333-133610 pertaining to the AmSouth Bancorporation 2006 Long Term Incentive Compensation Plan. 

/s/    ERNST & YOUNG LLP 

Birmingham, Alabama 

August 4, 2006