Dislocation of the shoulder is a common injury and may be associated with a variety of complications. We report six cases of primary replacement of the humeral head where closed reduction of a shoulder dislocation associated with an undisplaced fracture of the humeral neck led to displacement of the neck fracture. All dislocations examined were anterior with a displaced greater tubercle fracture. The patients had undergone closed reduction at of her medical centres and were referred to us because of iatrogenically displaced fracture-dislocations of the shoulder. Three were women and three were men with a mean age of 52.8 years (range 38-72). Primary replacement of the humeral head was done in an average of 9.3 days (range 2-30 days) following the injury. The average follow-up period was 30.2 months (range 12-55 months). Postoperative pain, active range of motion and function were evaluated with the American Shoulder and Elbow Surgeons Criteria. The forward flexion averaged 124 degrees, active external rotation averaged 29 degrees and internal rotation (achieved movement) to the second lumbar vertebra. Because of the high risk of avascular necrosis and severe collapse of the humeral head, we conclude that the primary replacement of the humeral head is the superior treatment option in iatrogenically displaced fracture dislocations of the shoulder. (C) 1998 Elsevier Science Ltd. All rights reserved.