There are many procedures for treatment of injuries of acromioclavicular separation but there are still con- roversies concerning the best management of these injuries. With this in mind, we treated surgically 22 cases of acromioclavicular separation of which 3 cases were old type 2 and 19 cases were type 3 in the department of orthopaedic surgery, Eul Ji General Hospital from March 1977 to darch 1982. The results were as follows: l. Of 22 cases, 21 cases (95.5%) were male with peak incidence in the 3rd and 5th decades (90.9%). 2. The most common causes of the injuries were traffic accidents (63.6%) and followed by falling from height (22.7%). 3. The diagnosis in type 2 and type 3 injuries is based on the clavicular displacement and instability at the acromioclavicular joint. 4. Operative treatment consists of Weaver and Dunn method (54.5%), modified Phemister method (18.2%), Neviaser method (13.0%), Stewart method (9.1%) and modified Henry method (4.5%). 5. The operative procedure in old type 2 and typc 3 injuries is good treatment of acromioclavicular separation.