Simultaneous total aortic replacement, including the arch and extending to bifurcation, has been performed in six cases at our institution. The cases presented were (1) acute dissection, including the intimal tear in the arch (one case); (2) chronic Type-I dissection, with both visceral and inferior limb ischemia (three cases); and (3) multiple aneurysms (two cases). The broad outline of the surgical technique employed consists of inducing general hypothermia with extracorporeal circulation. At core temperature of 20 degrees C, circulation is stopped and the aortic arch is replaced. Afterward, cerebral perfusion and total body perfusion are resumed at low flow, keeping body temperature between 20 and 24 degrees C. The intercostal orifices are attached to the side of the aortic graft, and the spinal cord is reperfused. Finally, during a period of hypothermic abdominal ischemia, the abdominal aorta is replaced, and subsequently, rewarming is started. This result is achieved by instituting extracorporeal circulation with two arterial return cannulae (in the ascending aorta and in a femoral artery), making it possible to continue the perfusion of both the upper and lower body during the stages of aortic occlusion. Two patients died from bleeding 3 to 6 hours after operation, and medullary injury was not ascertained; one patient died after 1 month without neurologic disturbances; three patients are alive and in good functional condition 6 to 27 months after operation. We believe that total simultaneous aortic replacement is feasible with the hypothermic technique.