We did a retrospective review of 32 patients who had undergone acute treatment for acromioclavicular joint dislocation (mean follow-up period 46 months) and 24 patients who had undergone surgery for chronic joint dislocation (mean follow-up period 51 months). All patients had a ligamentoplasty performed using the coracoacromial ligament. With the shoulder functional score described by Patte, we obtained 81% satisfactory results for the patients who underwent acute treatment and 79% satisfactory results for those who underwent late treatment. Because results in both groups were similar, we now treat only the more severe form of acute dislocation with surgery. Delayed surgery is indicated in those patients who have an unsatisfactory result after functional treatment.