A 34-year-old pregnant woman with Marfan’s syndrome in the 34th week of gestation was diagnosed with acute DeBakey type I aortic dissection. Immediately after cesarean section, she underwent emergent operation of combined total aortic arch and aortic root replacement using cardiopulmonary bypass, deep hypothermia and antegrade cerebral perfusion. Both maternal and fetal outcomes were good and uneventful. Pregnancy increases the risk of aortic dissection especially for patients with Marfan’s syndrome. Moreover it should be noted that cardiac surgery using cardiopulmonary bypass and deep hypothermia generally results in fetal loss. If fetal maturity can be confirmed as in our case, cesarean section should be done before cardiovascular surgery. We describe here a case of successful operation for mother and infant at the 34th week of gestation.