Renal vascular injuries are found relatively frequently after non-penetrating abdominal trauma. Penetrating renal arterial lesions occur much less frequently, involving less than 5 per cent of all penetrating arterial injuries. The association of bowel and other organ injuries makes diagnosis and treatment somewhat complex. Four cases of penetrating renal arterial injuries were seen from January 1972 to June 1976. All patients had multiple bowel lacerations. All arrived in the emergency room in hypovolemic shock. Two patients were resuscitated and successfully treated. Three patients had complete transections and 1 had major branch transection. Two patients had an associated parenchymal lesion. One patient had a through-and-through ureteropelvic injury. Preoperative arteriography was not done because of vascular instability. Renal arterial injuries were suspected by loss of psoas shadow on abdominal x-rays and by retroperitoneal hematomas. Retroperitoneal hematomas were explored to eliminate the possibility of renal injury. Both of the patients operated upon attained good renal function after surgical repairs. Postoperative renal scans and arteriograms showed initially decreased function, which returned toward normal. Repair of renal arterial lesions is possible with good functional result. Preoperative arteriography, renographic scan or excretory urography is not justified routinely because of the seriousness of commonly associated injuries.