Two patients with blunt renal injuries (Hodges grade I and II), and two further patients with spontaneous renal and/or retroperitoneal hemorrhage, were studied with excretory urography, isotope scanning, ultrasound, angiography, and computerized tomography. The most important additional information provided by the CT scan was the disclosure of small parenchymal lacerations, as well as the presence and extent of perirenal hematomas. These abnormalities could also be monitored with CT studies during the healing phases. Renal excursion studies during breathing and the usual tomography seem to be no longer necessary in renal trauma cases if one plans to utilize CT scanning. Likewise, the necessity for angiographic studies decreases. Ultrasound, however, may still be helpful in certain cases of perirenal hematoma.