1. Enteric coated sodium salicylate 4.8 g daily was compared with the same dose of enteric coated aspirin in 18 patients with rheumatoid arthritis. 2. After an initial washout period lasting 3 days, patients were randomly allocated to treatment with sodium salicylate or aspirin. After 2 weeks the two treatments were crossed over. 3. Pain relief, reduction in articular index of joint tenderness, increase in grip strength, decrease in digital joint circumference and patients' assessment showed significant improvement with both treatments compared with the washout period. No significant differences were found between the two therapies. 4. No correlation was found in the degree of improvement in any of the clinical outcomes and the salicylate concentrations at steady state.