15 cases of acute dislocation of the elbow were treated at Department of Orthopaedic Surgery, Capital Armed Forces General Hospital, Seoul, Korea during the period of March, 1985. To June, 1986 were analysed. The length of follow-up period ranged from 6 months to 16 months, with a mean of 9 months. The results were as follows; 1. 7 cases had been surgically treated, and they revealed rupture of the medial collateral ligament in all. So, we think that the medial collateral ligament of the elbow plays an important role in elbow stability. 2. The average immobilization period for the patient with non-operative treatm ent was 2 weeks. And normal ran ge of motion was obtained at 8 weeks. So, there was no. significant difference from other reports in the duration of recovery. 3. The period of recovery in operated patients was 14 weeks, and it was 6 weeks longer than non-operatively treated patients. 4. There was no chronic elbow instability in all 15 patients, but 3 cases with non-operative treatment complained of medial elbow pain on vigorous exercise.