A 26-year-old man with Marfan's syndrome suffered aortic dissection repeatedly during hospitalization. He was admitted with a diagnosis of annuloaortic ectasia with severe aortic regurgitation. A type A aortic dissection occurred after diagnostic angiography. Three weeks after the onset of the dissection, an aortic root replacement in combination with a total arch replacement was performed. Eight months later, residual dissection in the descending thoracic aorta was replaced with distal perfusion by a temporary bypass from the left subclavian artery to the descending thoracic aorta. At the termination of the operation, abdominal aortic dissection occurred with acute bilateral limb ischemia, which was treated with abdominal aortic intimal fenestration. He recovered uneventfully and was discharged 3 weeks after operation. In light of our experience, because of vascular fragility, great care should be taken in treating patients with Marfan's syndrome to avoid iatrogenic aortic dissection.