We have analyzed our results after 543 cup arthroplasties in 475 patients with a variety of hip disorders. Data concerning the operation itself, postoperative management, and complications have been presented. Two hundred fifty-one patients (294 hips) were examined three to sixteen years after operation. The results have been compared with the preoperative condition. Over-all improvement occurred in 90 per cent of the patients. Pain was completely relieved in two-thirds of the patients and improved in 90 per cent. The results in terms of gait, working ability, and activities of daily living were enumerated. Results were correlated with technical factors, clinical examination and roentgenographic findings. We concluded that cup arthroplasty is a useful procedure in the treatment of hip disease and have pointed out some of the areas where further improvement is needed.