We reviewed 27 patients who had sustained displaced three- or four-part fractures of the proximal humerus and who were treated with a humeral hemiarthroplasty. Seventeen patients had a three-part fracture, and 10 had a four-part fracture. The mean follow-up period was 39 months (12 to 94 months). All fractures were classified according to Neer's classification. The Constant score was used for their follow-up evaluation. The median Constant score at follow-up was 51 for the three-part fractures and 46 for the four-part fractures. The median range of movement for all the patients in flexion was 70 degrees, abduction 70 degrees, internal rotation 50 degrees, and external rotation 45 degrees. Nine patients still had moderate or severe pain. Eight patients had moderate or severe disability. Our results were disappointing, and further studies on open reduction and fixation are therefore justified.