Myositis ossificans presents as a painful soft tissue swelling, and 50% of patients give a history of significant blunt trauma. In 35 patients who were treated at Department of Orthopedic Surgery Seoul National University Hospital from Augst, 1982 to September, 1988, we analyzed 10 patients more than 1 year follow up and obtained following results. 1. Mean age was 35 years. (M:F = 9:1) 2. Locations were proximal and distal thigh in 7 patients, elbow in 3 patients. 3. Etiology was paraplegia and quadriplegia in 4 patients, concomittant with fracture or operation in 5 patients, spontaneously occured in 1 patient. 4. We performed conbined excision and radiation therapy in 6 patients, prophylactic diphosphonate in 3 patients and conservative therapy in 1 patient. 5. Complications were recurrence of myositis ossificans in 2 patients.