The authors evaluate after an interval of 1-20 years the long-term results of surgical synovectomy in 454 patients and radioactive synoviorthesis in 528 patients performed at the First Orthopaedic Clinic, Medical Faculty, Comenius University and Faculty Hospital in Bratislava and at the Orthopaedic and Traumatological Clinic of the Medical Faculty in Martin in 1969-1991. The most frequent diagnosis in surgical synovectomy is rheumatic synovitis in radioactive synovectomy arthrotic synovitis (47.6% and 68.6%). The authors evaluate both methods of synovectomy according to Aidem-Baker and compare the results of the two methods. They found significantly more very good and good results after surgical synovectomy (54.8% and 33.5%) as compared with radioactive synoviorthesis (15.5% and 38.0%). Conversely they found significantly more satisfactory and poor results in radioactive synoviorthesis (29.1% and 17.4%) than after surgical synovectomy (8.8% and 2.9%) which comprise patients relatively satisfied with this procedure and who do not agree with other procedures.