The conservative or surgical treatment of Rockwood grade III acromioclavicular dislocations continues to be a controversial subject. Thus, the authors report their experience with 52 cases; long-term follow-up was obtained for 40 of these, paying close attention to the preoperative clinical and radiographic evaluation and to the results obtained in order to ascertain whether or not surgical repair is required. The results of surgical treatment, however satisfactory (90% excellent or very good), are nearly the same as those obtained when non surgical treatment is used as reported in the international literature. The authors conclude that the use of surgical treatment must be limited to carefully selected cases, should prolonged conservative treatment fail. Of the three surgical techniques used, temporary stabilization of the acromioclavicular joint using AO wires associated with restoration of the coracoclavicular connections has proven to be more effective than Dall-Miles metal wiring and tangential resection, with a lower incidence of complication.