To explore the operative method and the cl inical outcomes of repairing acromioclavicular dislocation by clavicular hook plate internal fixation and coracoacromial l igament transposition. Methods From August 2004 to December 2007, 12 cases of acromioclavicular dislocation were repaired with the internal fixation of clavicular hook plate and the transposition of coracoacromial l igament. There were 9 males and 3 females aged 22-56 years old (average 32 yearsold). Causes of injury: 6 cases from fall ing injury, 4 cases from crush injury and 2 cases from traffic accident. There were 5 cases of the left acromioclavicular dislocation, and 7 cases of the right. According to acromioclavicular dislocation classification set by WANG Yicong, 8 cases were graded as type III, 3 cases as type IV, and 1 case as type V. The time from injury to operation was 3-28 days (average 6 days). The injured arm was hung after operation, and the function training was started 3-5 days after operation. Results All wounds healed by first intention, and the X-ray films showed complete reposition of acromioclavicular joints was achieved in all cases 1 week after operation. Over the follow-up period of 12-30 months, no plate and screw loosening, hook break and acromion fracture occurred. At 2 months after operation, 2 patients had sl ight pain when moving the shoulder, and the symptom disappeared when removing the plate. No re-dislocation was observed in all cases after removing the plate at 6-10 months after operation. The function of shoulder joint was assessed by Karlsson evaluation standard 1 year after operation, 11 cases were graded as excellent and 1 case was good. Conclusion For the repair of acromioclavicular dislocation, the method of combining clavicular hook plate internal fixation with coracoacromial l igament transposition has the advantages of minor wound, easy operation, l ittle influence on the function of shoulder joints, and rel iable restoration of the stabil ity of shoulder joint.