We determined the outcome of 113 total shoulder replacement arthroplasties performed with a Neer prosthesis between 1975 and 1981. The operations were performed for the treatment of osteoarthritis, rheumatoid arthritis, and old fractures or dislocations with traumatic arthritis. The probability of implant survival was 93% after 10 years and 87% after 15 years. Complications requiring reoperation developed in 14 shoulders. Seventy-nine patients with 89 replacements were available for follow-up a minimum of 5 years after the operation (mean 12.2 years, range 5 to 17 years). Relief from moderate or severe pain was achieved in 83% of shoulders. Active abduction improved by an average of 40 degrees to an average of 117 degrees. The amount of elevation that was regained was related to the amount of rotator cuff disease. Seventy-five glenoid components developed bone-cement radiolucencies, and 39 (44%) glenoid components had radiographic evidence of definite loosening. Glenoid loosening was associated with pain. A shift in position of the humeral component occurred in 49% of the press-fit stems and in none of the cemented stems. Humeral component loosening was not associated with pain.