A three-year retrospective study of synovectomies in children. The aim of this study was to evaluate the results of synovectomies in children with juvenile arthritis. Five hundred twenty-eight synovectomies and tenosynovectomies were performed over a period of 13 years. The patients were followed for one, two, three, five, and ten years postoperatively. The evaluation after three years was chosen as the basis for this article. One hundred twenty-five children with arthritis who were not evaluated three years postoperatively had less severe arthritis, both locally and generally, than the evaluated group of 389. The rate for good results and tolerability was high at one, two, and three years postoperatively but decreased with time; more patients went from good results to poor rather than vice versa. Global assessment, soft-tissue swelling, and limitation of movement seemed to be the best parameters for evaluating the results of synovectomies. It appears necessary to wait at least three years to evaluate the long-term effect of synovectomies. 