1 Exhibit 23.1 INDEPENDENT AUDITORS' CONSENT We consent to the incorporation by reference in Registration Statement Nos. 333-73039, 333-84071, 333-31676, and 333-33118 of DUSA Pharmaceuticals, Inc. on Form S-3 and Registration Statement No. 333-92259 of DUSA Pharmaceuticals, Inc. on Form S-8 of our report dated February 23, 2001, appearing in this Annual Report on Form 10-K of DUSA Pharmaceuticals, Inc. for the year ended December 31, 2000. s/DELOITTE & TOUCHE LLP Boston, Massachusetts March 15, 2001