Objective. Evaluation of a self-management program for patients with osteoarthritis (OA) of the hip or knee. The program, which consisted of 6 weekly sessions of 2 hours, included health education by a peer and physical exercises taught by a physical therapist. Methods. Randomized controlled trial. Inclusion criteria were diagnosis of OA of the hip or knee according to ACR clinical and radiographic criteria and age 55 to 75 years. Exclusion criteria: on waiting list for joint replacement. There were pretest, posttest, and followup (6 months) assessments. The experimental group consisted of 56 patients, the control group 49. Outcome variables were pain, quality of life, activity restrictions, knowledge about OA, self-efficacy, body mass index (BMI), and mobility measures. Attention was also paid to effects on health care utilization and lifestyle behavior. Results. Significant MANOVA group x time effects (p < 0.05, one-sided) were found for pain, quality of life, strength of the left M. quadriceps, knowledge, self-efficacy, BMI, physically active lifestyle, and visits to the physical therapist. Most effects were moderate at posttest assessment and smaller at follow-up. No effects were found for range of motion and functional tasks. Conclusion. The program was reasonably effective, but more attention should be paid to proactive followup interventions and to the selection of participants.