Twenty-one patients with rheumatoid arthritis had 33 knees treated with synovectomy. They were followed for an average of 5 2/3 years postoperatively. At follow-up, patients with 58% of the knees had less pain, 15% more pain, 54% were satisfied, 39% had palpable synovitis, but all had lesser synovitis postoperatively, and 53% showed radiographic progression of disease. Motion was not lost. There were no significant complications. Better results can be anticipated in those patients whose knees show little or no destruction radiographically and no significant deformity at the time of operation. However, beneficial results can occur even in those with more advanced changes. Even though quality of results tends to diminish with time, the procedure offers sufficient benefits to continue its use.