The clinical outcomes of 717 patients who underwent transurethral resection for benign prostatic hyperplasia between 1971 and 1981, and of 48 who underwent open prostatectomy during the same period were evaluated. All living patients could be followed for a minimum of 12 years postoperatively. The cumulative percentage of patients undergoing a secondary operation was substantially greater after transurethral resection of the prostate than after open prostatectomy. The volume of resected tissue, operating time, requirement for blood transfusion and hyponatremia during or after the procedure did not affect long-term outcome of patients in the transurethral resection group. Abnormal preoperative electrocardiography and azotemia appeared to be associated with increased risk of postoperative mortality after controlling for other variables (p < 0.05). Actuarial survival rates did not differ substantially for patients who underwent transurethral resection and open prostatectomy, and exceeded the expected survival rates in the general male population in the same age group in Japan. Both procedures are safe for the symptomatic relief of urinary obstruction due to benign prostatic hyperplasia. Prostatectomy does not jeopardize long-term survival of the patients.