Objective To investigate the cl inical efficacy, compl ications and necessity of removing internal fixation in treatment of fresh Tossy type III acromioclavicular joint dislocations and Neer type II distal clavicle fractures with clavicularhook plate. Methods From June 2005 to June 2008, 24 patients with fresh Tossy type III acromioclavicular joint dislocations and 20 patients with fresh Neer type II distal clavicle fractures were treated. There were 32 males and 12 females with an agerange of 18-66 years (38.5 years on average), involving 18 left shoulders and 26 right shoulders. The injury was caused bytraffic accident in 31 cases and by fall ing in 13 cases. The mean time from injury to operation was 4 days (range, 2-8 days). All patients were treated by reduction with clavicular hook plate fixation. The coracoclavicular l igaments were not sutured. The shoulder functions were evaluated according to University of Cal ifornia-Los Angeles (UCLA) score system and analysed before and after removing internal fixation. Results Wound infection occurred in 2 cases 1 week after operation and healed after symptomatic managment, the other incisions healed by first intention. One case accepted hook plate fixation again because of loosening hooking-up 1 week after operation. One case accepted hook plate removal and Kirschner wire fixation because of severe shoulder’s pain on the postoperative third day. Thirty-eight patients were followed up for 8-32 months (18 months on average), there was no plate breakage. Clavicle fractures got bony union after 3-6 months (4.2 months on average). At last followup (before plate removal), according to UCLA shoulder function score system, the results were excellent in 11 cases, good in 22 cases, and fair in 5 cases; the excellent and good rate was 86.8%. Because of shoulder’s pain, plates were removed in 20 patients 3-16 months (10 months on average) after operation. The cases were followed up 3-8 months (5 months on average) after removing plate. No dislocation and fracture occurred again. There was statistically significant difference (P lt; 0.01) in the functional scores of shoulder between before (30.55 ± 4.00) and after removing internal fixation (33.85 ± 1.95). Conclusion Clavicular hook plate fixation is an effective treatment for fresh Tossy type III acromioclavicular joint dislocations and Neer type II distal claviclefractures. Normative operating, correct plate moulding, functional rehabil itation after operation are key factors in preventingcompl ications and reaching good cl inical efficacy. For the patients with postoperative symptoms, the plate should be removed to improve the shoulder’s function.