Fifty-nine patients with acute gouty arthritis entered into a 7-day multicenter, double blind trial of ketoprofen versus indomethacin. Patients were randomly assigned to receive 100 mg of ketoprofen (n = 29 patients) or 50 mg of indomethacin (n = 30 patients) 3 times a day. More than 90% of the patients in each group reported pain relief within the 1st day of treatment. By Day 5, 7 patients in the ketoprofen group and 6 in the indomethacin group discontinued treatment because of complete or substantial pain relief. At the end of the study, most patients in both groups were rated as having marked improvement both by the investigators and by self-assessment. Three patients in each group withdrew prematurely because of drug related gastrointestinal disorders. Ketoprofen compared favorably for efficacy and safety with indomethacin in the treatment of gouty arthritis.