Exhibit 15 May 13, 1998 Securities and Exchange Commission 450 Fifth Street, N.W. Washington, D.C. 20549 Ladies and Gentlemen: We are aware that Phelps Dodge Corporation has incorporated by reference our report dated April 13, 1998 (issued pursuant to the provisions of Statement on Auditing Standards No. 71) in the Prospectus constituting part of its Registration Statement and Post-Effective Amendment No. 1 on Form S-3 (Nos. 33-44380 and 333-36415) and in the Registration Statements on Form S-8 (Nos. 33-26442, 33-6141, 33-26443, 33-29144, 33-19012, 2-67317, 33-34363, 33-34362, 33-62648, 333-42231 and 333-52175). We are also aware of our responsibilities under the Securities Act of 1933. Yours very truly, Price Waterhouse LLP Phoenix, Arizona