Transrectal ultrasonography (TRUS) in prostate cancer could show the images of multiform prostate adenomas. Specific sign is a hypoechoic area in periphery of gland. Overall, sensitivity (32%) and specificity (51%) of TRUS in diagnosis prostate cancer weren’t high. The false negative was from 30% to 40%. Two major roles of TRUS were to determine suspected lesions and to increase accuracy of prostate biopsy. TRUS techniques in diagnosis prostate cancer were: conventional TRUS, TRUS with Doppler, TRUS with contrast Doppler, and TRUS with 3D ultrasound. Under TRUS-guiding, biopsy can be performed through perineum or rectum