Drug-induced meningitis should be considered in differential diagnosis of meningeal irritation in patients receiving therapy with anti-infective, nonsteroidal anti-inflammatory, immunosuppressive, or other selected agents. This report describes a case of aseptic meningitis associated with use of trimethoprim-sulfamethoxazole in a patient without apparent underlying autoimmune disease. The patient recovered promptly after the offending agent was withdrawn. No specific treatment other than symptomatic and supportive care need be given. In all instances, however, infection must be excluded.