Exh 23.1 Consent of Independent Registered Public Accounting Firm (POS AM 03)

We consent to the reference to our firm under the caption “Experts” in this Post-Effective Amendment No. 3 to Form S-3 Registration Statement (No. 333-171953) of Lexicon Pharmaceuticals, Inc. and to the incorporation by reference therein of our reports dated March 15, 2011, with respect to the consolidated financial statements of Lexicon Pharmaceuticals, Inc. and the effectiveness of internal control over financial reporting of Lexicon Pharmaceuticals, Inc., included in its Annual Report (Form 10-K) for the year ended December 31, 2010, filed with the Securities and Exchange Commission.