The prostate glands of 84 men undergoing cystoprostatectomy for bladder cancer were examined by whole-mount sections at 4-mm to 5-mm intervals to identify unsuspected prostate adenocarcinoma (PCa). Of 72 white patients with entirely normal digital rectal examinations (DRE), 33 (46%) were found to have PCa, including 12 (17%) who had a Gleason score of 6 or greater and seven (10%) who had penetration through the prostatic capsule. These observations are consistent with previous studies in autopsy populations but allow a more appropriate comparison with morphologic data generated from radical prostatectomy specimens. If these data can be extended to the age-matched general population, treatment at a 1% mortality rate for all white men 60 to 74 years of age with a PCa with a Gleason score of 6 or greater could cause between 6190 and 30,951 deaths, in contrast to 7335 deaths expected from the cancer. These data stress the need for a control group in a study designed to evaluate the benefit of early diagnosis and treatment of PCa.