Exhibit 23.1 CONSENT OF INDEPENDENT ACCOUNTANTS We hereby consent to the incorporation by reference in this Registration Statement on Form S-8 of our report dated February 18, 2003, except for Note F as to which the date is June 23, 2003, relating to the consolidated financial statements of Sanofi~Synthelabo included in its Annual Report (Form 20-F) for the year ended December 31, 2002 filed with the Securities Exchange Commission. Paris, France July 22, 2003 Ernst & Young Audit /s/ Jean-Claude Lomberget /s/ Valerie Quint - ------------------------- ----------------- Jean-Claude Lomberget Valerie Quint