Retrosternal displacement of the medial aspect of the clavicle after physeal fracture is rare. We treated six patients with this injury between 1995 and 1998, all as an emergency in order to avoid complications associated with compression of adjacent mediastinal structures. Attempted closed reduction was undertaken, but all required open reduction and internal fixation using a wire suture. There were no associated complications. Five were reviewed clinically and radiologically at a minimum of one year after operation. All had regained full use of the affected arm without pain and had resumed their preinjury level of activity including sports. Follow-up radiographs showed union in the anatomical position in all patients. We recommend attempted closed reduction in the operating room, followed, if necessary, by open reduction. Internal fixation after open reduction gives stable fixation with minimal morbidity.