Of seventy-seven total shoulder-replacement arthroplasties with a Neer prosthesis, I evaluated seventy-three replacements in sixty-five patients at two to six and one-half years after the operation. The operations were performed for the treatment of osteoarthritis, rheumatoid arthritis, and old fractures or fracture-dislocations with traumatic arthritis. Postoperatively there was little or no pain even with vigorous activities in most shoulders, and active abduction improved by an average of 44 degrees, to an average of 120 degrees. The amount of abduction that was regained was related to the original diagnosis and to the amount of rotator cuff disease. Complications developed in thirteen shoulders, and five reoperations were necessary. Eight glenoid components showed radiographic evidence of loosening. Fifty-two of the remaining sixty-five shoulders had some radiolucency at the glenoid bone-cement junction.