Malperfusion of the thoracoabdominal aorta or its branches is a common complication of aortic dissection, often with a fatal outcome. Since 1985 we saw thoracoabdominal malperfusion in 13 patients with aortic dissection. During repair of an acute type A aortic dissection, the intimal flap was fenestrated in three cases in the abdominal aorta and one within the superior mesenteric artery. In two cases with acute type B aortic dissection fenestration was performed at the level of the aortic bifurcation, and in one the descending aorta was replaced. Six patients had chronic dilatation of a false lumen without distal reentry, compromising the true lumen, with malperfusion of viscera, kidneys, and lower extremities. Three patients underwent replacement of the descending aorta, two of them subsequent abdominal aortic replacement with revascularization of the kidneys. One patient had thoracoabdominal replacement, and in two an extra-anatomic bypass was implanted. Five patients with acute dissection died: two from sequelae of malperfusion, two of myocardial failure, and one late after stroke. Eight patients are alive 1 month to 5 years after operation. In acute aortic dissection fenestration of the intimal flap may relieve thoracoabdominal malperfusion. In chronic aortic dissection, pseudocoarctation is most likely to occur at the diaphragmatic hiatus. This is treated by replacement of the affected aortic segment. In high-risk patients an extra-anatomic bypass is also feasible.