A follow-up of 78 patients with acromio-clavicular dislocation who have been operated on since 1956 is reported. The tendon of the short head of the biceps is transferred to the clavicle to obtain, and maintain, reduction. The site of transfer in the last 51 cases has been to a point on the clavicle immediately above the coracoid process. The acromio-clavicular joint is only opened when an obstruction to reduction is present. The functional results in this group of patients are very good.