Background: Of cardiovascular manifestations in Marfan syndrome (MFS), aortic dissection is a substantial contributor to premature mortality among MFS patients. We hypothesized that patients with aortic dissection and MFS show different behaviors and prognosis from those with aortic dissection and non-MFS. We compared the clinical presentation, dissection characteristics, and outcomes of patients with or without MFS among Korean population. Methods: We reviewed patients with aortic dissection who were diagnosed from December 1994 to March 2009 at our institute. Clinical observation was conducted for 34 짹 35 months and all patients underwent serial multi-detector CT (MDCT) exams during follow-up period. Variables of interest included demographics, histories, imaging results and management strategies. The following parameters to evaluate clinical outcomes were analyzed: significant progression of dissection, re-operation for recurrent aortic dissection/aneurismal dilatation, and death. Results: Of the 464 patients with aortic dissection, 53 patients (11.4%) had MFS. Compared with non-Marfan patients, patients with MFS more likely developed aortic dissection at younger age (33 짹 10 vs 57 짹 13 years, p < 0.0001), had prior cardiac surgery (13.2% vs 2.9%, p = 0.003) and less tended to be hypertensive (9.4% vs 74%, p < 0.0001). Aortic root dilatation and accompanying aortic valve regurgitation were more prominent in patients with MFS (p < 0.0001). Despite a similar incidence of type A aortic dissection between patient with and without MFS (66.0% vs 56.9%, p = 0.238), surgical repairs were more likely undergone in those with MFS (81.1% vs 65.1%, p = 0.020). During follow-up periods, patients with MFS were more likely to develop aortic dilatation and expansion of dissection (43.8% vs 21.8%, p = 0.003) and showed higher rate of re-operation (32% vs 8.7%, p < 0.0001). Overall mortality in patients with MFS were far worse than those without MFS (45.8% vs 24.5%, p = 0.0062). Conclusion: Our study demonstrated that different characteristics and higher mortality of aortic dissection in patients with Marfan syndrome compared with non-Marfan patients. Based on these finding, we emphasize the importance of accurate diagnosis and surveillance of MFS as well as timely management including prophylaxis in patients with aortic dissection.