The clinical synovitis and radiological destruction of wrist and subtalar joints were followed over a 3-year period in 107 patients with rheumatoid arthritis of no longer than 6 months' duration. The joints were examined clinically and by X-ray on entry to study, at one year and at three years of study. The progress of joint destruction was highly significantly correlated with the frequency of clinical synovitis at the three examinations in both wrist and subtalar joints.