Although the results of surgical treatment for acute type A dissection have improved because of progress in surgical techniques, the prognosis is still very poor and optimal therapeutic approach is still not clearly established for cases of acute dissection complicated with malperfusion. Of 134 patients who presented with acute aortic dissection between January 1986 and June 1999, 57 had acute type A dissection and 10 had acute type A dissection with malperfusion. Patient age ranged from 53 to 78 (average, 64.6) years. There were 6 men and 4 women. There was accompanying cerebral ischemia in 3 cases, coronary ischemia in 1, visceral ischemia in 5, renal ischemia in 2, ischemia of the extremities in 7, and multiple organ ischemia in 5. One patient died before surgery, and another patient died after sternotomy due to aortic rupture. The other 8 patients underwent surgical operations. The following surgical procedures were performed: bypass grafting to the superior mesenteric artery was performed in 1 patient, stent implantation to the right coronary artery followed by ascending aortic replacement (19th day after onset) was performed in 1, and aortic repair (5 ascending aortic replacements and 1 hemiarch replacement) in the acute phase was performed in 6. The mortality rates were 66.7% (2/3) in patients with cerebral ischemia, 0% (0/1) in the patient with coronary ischemia, 80% (4/5) in those with visceral ischemia, 100% (2/2) in those with renal ischemia, 42.9% (3/7) in those with ischemia of the extremities, 80% (4/5) in those with multiple organ ischemia, and 50% (5/10) in all cases. All patients whose base excess (B.E.) was less than -10mEq/l on admission died (4/4). We conclude that in order to improve surgical results in patients with acute type A dissection with malperfusion, different approaches may be required for each patient. The combination of aortic repair and percutaneous reperfusion are important. Arterial blood gas analyses were simple, and the values of B. E. at admission were useful to determine the surgical strategy in these patients and to predict their prognosis.