We prospectively studied 103 men who had normal results on digital prostate examinations but had bladder outlet obstruction secondary to prostatic hypertrophy and needed transurethral prostatectomy. All men underwent a preoperative transrectal ultrasonographic examination of the prostate and prostate-specific antigen (PSA) level determination. A total of 30 cancers were ultimately detected, 22 (73%) of which were detected preoperatively by either an abnormal ultrasonogram or elevated PSA levels (or both). Eight of these men were spared transurethral prostatectomy and had definitive treatment based on transrectal biopsy and appropriate staging evaluation. For PSA and ultrasonography combined, the sensitivities and negative predictive values for cancer (92% and 94%, respectively) were superior to the specificities and positive predictive values (71% and 64%, respectively). The combined use of both studies is recommended to rule out cancer in candidates for prostatectomy but not to routinely screen the general male population older than 40 years.