EXHIBIT 23.1 INDEPENDENT AUDITORS' CONSENT We consent to the incorporation by reference in Registration Statement Nos. 33-90854 and 333-36597, 333-63706 and 333-90480 of ARIAD Pharmaceuticals, Inc. on Form S-8 and Registration Statement Nos. 33-85166, 333-51687, 333-63708 and 333-76486 of ARIAD Pharmaceuticals, Inc. on Form S-3 of our report dated March 13, 2003, appearing in this Annual Report on Form 10-K of ARIAD Pharmaceuticals, Inc. for the year ended December 31, 2002. /s/ DELOITTE & TOUCHE LLP Boston, Massachusetts March 13, 2003 78