An emergency saphenous vein bypass was performed from the right internal iliac artery to the superior mesenteric artery for ischemia due to occlusion of the superior mesenteric artery complicated with acute DeBakey type I aortic dissection. A 68-year-old woman underwent ascending aortic graft replacement for acute aortic dissection as emergency procedure. On postoperative day 4, signs and symptoms of acute mesenteric ischemia clearly developed. Laparotomy was performed and the saphenous vein graft was used to bypass the right internal iliac artery and the superior mesenteric artery at the orifice of the ileocolic artery where it was free from dissection. Because of persistent diarrhea and cramping abdominal pain, second- and third-look operations were necessary in order to confirm the recovery of intestinal viability. The patient was discharged from hospital with complete relief of abdominal symptoms 110 days after the first operation.