<PAGE>

                                                                 Exhibit 31(a)

            Certification of Chief Executive Officer Pursuant to
                Section 302 of the Sarbanes-Oxley Act of 2002

I, John C. Hunter III, certify that:

1. I have reviewed this quarterly report on Form 10-Q of Solutia Inc.;

2. Based on my knowledge, this report does not contain any untrue statement
of a material fact or omit to state a material fact necessary to make the
statements made, in light of the circumstances under which such statements
were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial
information included in this report, fairly present in all material respects
the financial condition, results of operations and cash flows of the
registrant as of, and for, the periods presented in this report;

4. The registrant's other certifying officer and I are responsible for
establishing and maintaining disclosure controls and procedures (as defined
in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the registrant and have:

         a) Designed such disclosure controls and procedures, or caused such
         disclosure controls and procedures to be designed under our
         supervision, to ensure that material information relating to the
         registrant, including its consolidated subsidiaries, is made known
         to us by others within those entities, particularly during the
         period in which this report is being prepared;

         b) Evaluated the effectiveness of the registrant's disclosure
         controls and procedures and presented in this report our
         conclusions about the effectiveness of the disclosure controls and
         procedures, as of the end of the period covered by this report
         based on such evaluations; and

         c) Disclosed in this report any change in the registrant's internal
         control over financial reporting that occurred during the
         registrant's most recent fiscal quarter (the registrant's fourth
         fiscal quarter in the case of an annual report) that has materially
         affected or is reasonably likely to materially affect, the
         registrant's internal control over financial reporting and;

5. The registrant's other certifying officer and I have disclosed, based on
our most recent evaluation of internal control over financial reporting, to
the registrant's auditors and the audit committee of registrant's board of
directors (or persons performing the equivalent functions):

         a) All significant deficiencies and material weaknesses in the
         design or operation of internal control over financial reporting
         which are reasonably likely to adversely affect the registrant's
         ability to record, process, summarize and report financial
         information; and

         b) Any fraud, whether or not material, that involves management or
         other employees who have a significant role in the registrant's
         internal control over financial reporting.

Date: November 14, 2003

                                             /s/ John C. Hunter III
                                            -----------------------
                                               John C. Hunter III
                               Chairman, President and Chief Executive Officer