One hundred fifty consecutive Marfan patients undergoing composite graft repair of an ascending aorta aneurysm are reported. Twenty-six of the 150 patients had a preoperative dissection of the ascending aorta. There were no early deaths among 138 patients undergoing elective composite graft repair. There was one early death among 12 patients undergoing urgent operation; this patient arrived at the hospital with a rupturing aneurysm. Twenty-four of the 150 patients had mitral procedures; there were no early deaths in this group. There have been 14 late deaths among the 149 hospital survivors (9%). Actuarial survival of 150 patients at 1, 5, 10, and 14 years was 93%, 92%, 81%, and 73% respectively. Risk factors for early or late death were identified by multivariate analysis and only New York Heart Association class (III or IV) and male gender emerged as significant independent predictors of mortality. Late complications directly related to the composite graft have been gratifyingly low; only 2 patients had coronary dehiscence and 3 had thromboembolic events. Endocarditis emerged as an important late complication in 8 patients (5%). Two patients were successfully treated with antibiotics, 3 died before widespread availability of cryopreserved homografts, and 3 patients treated with antibiotics and homograft root replacement have had no evidence of recurrent infection. Seven patients with dissection in this series had aortic diameters of 6.5 cm or less. This experience supports the concept that composite graft repair in Marfan patients is mandated when the aneurysm reaches 5.5 to 6 cm, even in the asymptomatic patient.(ABSTRACT TRUNCATED AT 250 WORDS)