The authors evaluated the risk of death from prostate cancer in Rhode Island men who had had surgery for prostatic hypertrophy during the years 1959-1970. The retrospective follow-up method was used. Among 4,853 men who had had either a transurethral resection or a prostatectomy, age- and time-standardized mortality from prostate cancer was 1.14 (95% confidence interval (CI) 0.93-1.33) times the rate in the general population of Rhode Island men. The age- and time-standardized mortality ratio was 1.01 (95% CI 0.77-1.31) for men who had had a suprapubic prostatectomy and 1.18 (95% CI 0.94-1.47) for men who had had a transurethral resection. The authors used the case-control method to relate the histologic features of prostatic hypertrophy to subsequent prostate cancer. The observed associations were weak and inconsistent. The results of this study suggest that surgically treated prostatic hypertrophy is not an important determinant of prostate cancer.