EXHIBIT 15.1 INDEPENDENT ACCOUNTANTS' AWARENESS LETTER Securities and Exchange Commission 450 Fifth Street, N.W. Washington, D.C. 20549 Ladies and Gentlemen: We are aware that Diamond Shamrock, Inc. has included our report dated May 11, 1995 (issued pursuant to the provisions of Statement on Auditing Standards No. 71) in the Prospectus constituting part of its Amendment No. 1 to the Registration Statement on Form S-3 (No. 33-59451) to be filed on or about June 22, 1995. We are also aware of our responsibilities under the Securities Act of 1933. Yours very truly, /S/ PRICE WATERHOUSE LLP PRICE WATERHOUSE LLP San Antonio, Texas June 22, 1995 W2930.TW