OBJECTIVE To evaluate the vascular anatomy of the prostate gland with transrectal color Doppler ultrasound (US). METHODS Thirty-five normal prostate glands were studied. Imaging findings were interpreted on the basis of findings from previous anatomic studies. RESULTS Distribution of flow signals within the gland was differentiated into two parenchymal groups of arteries, urethral and capsular. The urethral group entered the prostate at the bladder neck and sent forth branches to supply the periurethral zone and the inner portion of the gland. The capsular group coursed along the anterolateral surface of the prostate and sent forth perforating branches to the outer portion of the gland. Intraprostatic venous signals were seen mainly within the periurethral zone. CONCLUSIONS Transrectal color Doppler US can depict the vascular anatomy of the prostate gland. Knowledge of the normal vascular appearance of the gland should aid in the differentiation of normal from abnormal findings.