EXHIBIT 23.1 INDEPENDENT AUDITORS' CONSENT We consent to the incorporation by reference in the Shire Pharmaceuticals Group plc Registration Statements on Form S-8 (Nos. 333-09168, 333-93543, 333-60952, 333-91552, 333-111579 and 333-111108), Form S-4 (333-55696) and Form S-3 (Nos. 333-72862-01, 333-38662 and 333-39702) of our report dated March 10, 2004, appearing in this Annual Report on Form 10-K of Shire Pharmaceutical Group plc for the year ended December 31, 2003. /s/ Deloitte & Touche LLP - -------------------------- DELOITTE & TOUCHE LLP Chartered Accountants Reading March 10, 2004