BACKGROUND: The arthritis of rheumatic fever is very responsive to treatment with salicylates, but there are many adverse reactions, especially hepatotoxicity, due to aspirin (acetylsalicylic acid) therapy. These side-effects change the course and duration of rheumatic fever. Other non-steroidal anti-inflammatory drugs may be equally effective, although no reports are available. METHODS: We studied 72 patients with rheumatic fever who were admitted to Dr Sami Ulus Children's Hospital between 1995 and 1999. Twenty patients with arthritis were treated with tolmetin (25 mg/kg per day; group I) and 52 patients with arthritis and/or mild carditis were put on aspirin therapy (75-100 mg/kg per day) for 4-6 weeks (group II). Arthritis had disappeared at the same time in both the aspirin and tolmetin groups (P = 0.675). RESULTS: The erythrocyte sedimentation rates of patients upon admission, at the first week and at the end of therapy were not different in the two groups (P > 0.05). No adverse effect of tolmetin therapy was observed, whereas side-effects of salicylate were observed in 19 patients (36.5%) in the aspirin group. Hepatotoxicity, gastric irritation and salicylism were found in 16, four and three patients, respectively. Renal toxicity and Reye syndrome were not demonstrated. Because of these side-effects of aspirin, therapy had to be stopped for 10-20 days and the duration of hospitalization in this group was lengthened unnecessarily. CONCLUSION: Tolmetin was safe and effective treatment for arthritic rheumatic fever patients without carditis. Tolmetin can be used particularly in patients who cannot tolerate aspirin.