There are various kinds of operative methods for the treatment of acute acromioclavicular dislocation but many complications such as posttraumatic arthritis, limitation of shoulder motion, and recurrence of dislocation would be developed. We have experienced 23 cases of acute acromioclavicular dislocation treated by modified Phemister technique from January 1992 to January 1997 and followed-up at least 1 year at Department of Orthopaedic Surgery, Pusan City Medical Center. The results were as follows: 1. The clinical results were evaluated by Weaver and Dunn were good in 19 cases, fair in 3 cases, poor in 1 case. 2. The radiological results were evaluated by the difference of the distance from the coracoid process to the clavicle between normal and injured site. The comparison of coraco- clavicular distance after surgery(1.76mm) with that of follow up(2.41mm) showed no significant difference(P>0.05, by Student t-test). 3. There was no posttraumatic arthritis and limitation of shoulder motion in all cases. So we suggest that modified Phemister technique is a good method for aute acromioclavicular dislocation.