Surgical treatment of cardiovascular complications in patients with Marfan's syndrome is usually recommended with apprehension since the systemic nature of the disease predisposes to early and late complications. To define the incidence of these complications, 30 patients were evaluated after surgical treatment of aortic insufficiency and ascending aortic aneurysm at the Texas Heart Institute. To provide a minimal follow-up period of 5 years, only patients operated upon during of before 1968 were included in this series. There were 9 female and 21 male patients aged 4 to 80 years (mean 44 years). Aortic insufficiency was treated by valvuloplasty in 3 patients and by aortic valve replacement in 27. Graft replacement of the ascending aorta was required in 23 patients, and the aneurysm was excised and the aorta repaired by direct anastomosis in 7. Two patients were lost to follow-up study; 12 of the remaining 28 (42.8 percent) lived 5 years or more. The hospital mortality rate was 20 percent (6 of 30); the causes of death included dissection or rupture of the aorta in three patients, congestive heart failure in two and pulmonary embolism in one. The 24 survivors lived from 5 weeks to 9 years. Follow-up data were available on 22 of these patients. Ten of these (45.4 percent) died of late complications. Seven died suddenly, four of these had redissection, one patient had occlusion of the right coronary artery, and two had ventricular fibrillation of no apparent cause. The remaining three died of noncardiac causes. Although the risk of ascending aortic and aortic valve surgery in patients with Marfan's syndrome is high, 42.8 percent of the patients in our series survived 5 years or more. We believe that surgery should be recommended for patients with Marfan's disease who have dissection of the aorta or severe aortic regurgitation, or both.