Exhibit 23.1 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We consent to the use in this Registration Statement on Form S-1 of our report dated October 12, 2005 relating to the financial statements of Bioenvision, Inc. and subsidiaries appearing in the Prospectus, which is part of this Registration Statement. We also consent to the reference to us under the headings "Experts" in such Prospectus. Parsippany, New Jersey December 14, 2005