Type A aortic dissection still presents an emergency situation in cardiac surgery that is associated with high morbidity and mortality rates. There has been a significant improvement in the surgical outcome since the introduction of deep hypothermia and circulatory arrest. In this study, we discuss our results after operative repair of ascending aortic dissections, using deep hypothermia and circulatory arrest. This study presents the results of 67 patients (43 men, 24 women) from 18 through 81 years of age (mean, 54 years) who underwent surgery for type A dissecting aneurysm over a period of 4 years. Type A dissection (52 acute and 15 chronic cases) was due to Marfan syndrome in 12 patients, to atherosclerotic disease of the aorta in 27 patients, and to traumatic injury in 1 patient. Hypertension as the only pathologic finding was observed in 27 patients. Deep hypothermia (confirmed by isoelectric electroencephalogram) and circulatory arrest were induced in all patients. Two patients died intraoperatively due to massive bleeding (intraoperative mortality, 3%). The 30-day mortality rate was 30% (n = 20). Causes of perioperative deaths in order of frequency were multi-organ failure (n = 11), myocardial infarction (n = 2), postoperative bleeding (n = 2), cerebrovascular insult (n = 2), and sepsis (n = 1). The mean intensive care unit stay of the surviving 47 patients (72%) was 8 days, followed by a mean of 21 additional days in the hospital. Our experience with profound hypothermia and circulatory arrest, used in combination with coated grafts, supports our conviction that this is the method of choice for the treatment of type A dissecting aneurysm.