EXHIBIT 23(a) INDEPENDENT AUDITORS' CONSENT We consent to the incorporation by reference in Registration Nos. 333-34561, 333-34587, 333-34589, 333-34591, 333-34593, 333-34683, 333-35689, 333-47911, 333-51081, 333-74463, 333-74465, 333-32112 and 333-39972 of Solutia Inc. on Form S-8 and Registration Statement Nos. 333-75812, 333-89818, and 333-99705 of Solutia Inc. on Form S-3 of our report dated March 15, 2004 (which expresses an unqualified opinion and includes explanatory paragraphs referring to Solutia Inc.'s filing for reorganization under Chapter 11 of the United States Bankruptcy Code, substantial doubt about Solutia Inc.'s ability to continue as a going concern and changes in accounting principles), appearing in this Annual Report on Form 10-K/A of Solutia Inc. for the year ended December 31, 2003. /s/ Deloitte & Touche LLP Deloitte & Touche LLP St. Louis, Missouri March 15, 2004