We treated 31 cases of olecranon bursitis and 19 cases of prepatellar bursitis. The average duration of symptoms before surgery was 1.1 years with a range of 3 months to 4 years. All patients had had preoperative aspiration and injection of cortisone. Patients underwent an arthroscopic bursal resection, removing all the bursal sack that could be seen. The results indicated that 86% of patients after olecranon bursectomy had no pain whatsoever. In the patients with prepatellar bursitis, 66% had no pain whatsoever, but we did note some residual tenderness in 24% of the patients, and 10% had pain on kneeling. There were 2 recurrences; 1 patient had rheumatoid arthritis and 1 repetitive daily trauma to the knee. There were no significant complications.