Two large-scale open-label studies were performed in France to confirm the efficacy and safety of etodolac (Lodine), a new non-steroidal anti-inflammatory drug (NSAID). Study I, a 6-week study performed by 974 rheumatologists, involved 4947 patients who had rheumatoid arthritis (RA), ankylosing spondylitis (AS), or osteoarthritis (OA). Both efficacy and safety were assessed. Study II, a postmarketing safety study performed by approximately 9000 general practitioners, involved 51,355 patients who had rheumatic conditions requiring therapy with NSAIDs. The daily dose of etodolac ranged from 200 to 600 mg/day in these studies, depending on the protocol and patient response. By the end of study I (visit 3), spontaneous pain improved by 33% for patients with RA, by 42% for patients with AS, and by 50% for OA patients. A total of 1276 adverse reactions (AR) were reported during the study, and fewer than half of these were related to study treatment. Only 6 severe reactions were reported; three of these were considered unrelated to study treatment, including 2 deaths. In study II, 10.1% of patients reported 6236 ARs and 9.0% of patients dropped out because of AR. Twenty-one of the ARs reported in study II were judged severe, and all of these patients recovered completely. The overall opinion of safety was assessed as very good or good by 89% of patients. In both studies (greater than 55,000 patients), 11% of patients reported an AR, and severe reactions were rare. These results confirmed the very acceptable risk/benefit ratio of etodolac and rank this drug high for efficacy and safety among the NSAIDs recently introduced in France.