A long-axis real-time ultrasonic transrectal probe was utilized in transperineal biopsies to detect three nonpalpable prostate cancers. It was found that ultrasonically guided percutaneous perineal biopsy allows for the accurate placement of the biopsy needle tip into suspicious areas of the prostate. Ultrasonographic examination prior to biopsy is recommended to provide confirmation of palpable masses and to reveal other suspicious but not clinically suspected areas.