The Oscobal-Daubenspeck hip prosthesis was used in 19 hemiarthroplasties and 38 total hip arthroplasties in 1973-1975 and the 10-year experience is presented. Pain recurred some years after the operation. The reason was wear of the high-density polyethylene prosthesis head, most pronounced in the hemiarthroplasties, resulting in wear-debris synovitis, resorption of bone, and mechanical loosening of the prosthesis. This design of prosthesis should not be used.