Description: Background— Data on outcomes after Stanford type A aortic dissection in patients with Marfan syndrome are limited. We investigated the primary surgery and long-term results in patients with Marfan syndrome who suffered aortic dissection. Methods and Results— Among 1324 consecutive patients with aortic dissection type A, 74 with Marfan syndrome (58% men; median age, 37 years [first and third quartiles, 29 and 48 years]) underwent surgical repair (85% acute dissections; 68% DeBakey I; 55% composite valved graft, 30% supracoronary ascending replacement, 15% valve-sparing aortic root replacement; 12% total arch replacement; 3% in-hospital mortality) at 2 tertiary centers in the United States and Europe over the past 25 years. The rate of aortic reintervention with resternotomy was 24% (18 of 74) and of descending aorta (thoracic+abdominal) intervention was 30% (22 of 74) at a median follow-up of 8.4 years (first and third quartiles, 2.2 and 12.7 years). Freedom from need for aortic root reoperation in patients who underwent primarily a composite valved graft or valve-sparing aortic root replacement procedure was 95±3%, 88±5%, and 79±5% and in patients who underwent supracoronary ascending replacement was 83±9%, 60±13%, 20±16% at 5, 10, and 20 years. Secondary aortic arch surgery was necessary only in patients with initial hemi-arch replacement. Conclusions— Emergency surgery for type A dissection in patients with Marfan syndrome is associated with low in-hospital mortality. Failure to extend the primary surgery to aortic root or arch repair leads to a highly complex clinical course. Aortic root replacement or repair is highly recommended because supracoronary ascending replacement is associated with a high need (〉40%) for root reintervention.