Several studies have shown the effectiveness of reconstruction of acromioclavicular ligament with coracoacromial ligament in treating the Grade III acromioclavicular joint injury. One of these is a bone block transfer of coracoacromial ligament into the medutlary canal of the clavicle to prevent occasional pullout of the transfered ligament. Eleven cases with complete acromioclavicular dislocation(acute 3, chronic 8) were treated by this method. We modified slightly the original method described by Shoji et al. to increase the success rate. Failure of coracoclavicular reconstruction occurred in two cases. All except one patient regained nearly painless range of shoulder motion. One patient showed severe restriction of shoulder abduction and definite deformity. In functional evaluation by the Weitzman criteria, five were excellent, four good, one fair, and one poor. Radiologic results for restoration of coracoclavicular interval showed marked improvement but were not consistent with clinical results. Main technical problems were harvesting bone block and fixation of ligament. To obtain good osseus healing without pull out of transferred ligament, we found that preservation of bone ligament junction and careful harvest of full thickness acromial hone block was important.