Stanford type A aortic dissection after graft replacement of ascending aorta and/or aortic arch required careful follow-up due to progression of the enlarged false lumen or the recurrence of dissection. From June 1984 to June 200, 124 patients underwent operations for type A aortic dissection. Among them, 6 patients underwent reoperation due to recurred aneurysm or dissection. We evaluated that the causes of reoperation, including Marfan syndrome, the approach and result of reoperation, and strategy to reduce the risk of reoperation. Material and method: The first operation was done on acute stage in 4 cases, and chronic stage in 2 cases. There were Marfan syndromes in 3 cases. The entry site was the ascending aorta for all cases except one who underwent Bentall operation(n=3) or ascending aorta graft replacement(n=2). In one case, Bentall operation and total arch replacement was performed due to chronic type A dissection with multiple fenestrations. Mean interval of reoperation was 67.6months(range 5 months to 14 year 4months) after the first operation. Reoperations were performed with recurrence of dissection(n=4), threatening aneurysmal evolution of persisting dissection(n=1), and false aneurysm with infection(n=1). The redo operation involved the hemiarch in 1 case, distal ascending to total arch and descending thoracic aorta in 4 cases, and only descending thoracic aorta in 1 case. Result: There were Marfan syndromes in 18 patients. The mean age in type A dissection was 56.7 years and that in the first operation of reoperationc ases was 32.2 years. Especially in 3 patients with Marfan syndrome, the mean age was 29 years.