It is difficult to predict the outcome of comminuted fractures of the proximal humerus and give guidelines for optimal treatment. Different treatment modalities are available, and there are various scoring systems for postoperative evaluation. The aim of this study was to assess the functional outcome after three- and four-part fractures of the humeral head in 38 patients, with a 3-year follow-up. Twenty-eight patients were treated conservatively, seven were operated on with open reduction and internal fixation, and three received a hemiarthroplasty. All patients were examined clinically and radiographically. Neer and Constant scoring systems were used. The functional outcome after three-part fractures was generally good. Twenty-five of 26 patients with a three-part fracture could accept their shoulder situation. Range of motion was significantly lower in the four-part fracture group. Mean flexion was 89 degrees compared with 120 degrees in the three-part fracture group. Necrosis of the humeral head was found in 2 cases, both four-part fractures. Osteoarthrosis developed in 13 cases (6 with a three-part fracture, 7 with a four-part fracture). No disability was found in 16 of 24 patients with three-part fractures, and in 4 of 11 patients with four-part fractures. There was strong agreement between the Constant score and the patients' opinions.