The aim of the study was to assess the long-term results of surgical treatment with homogenic aortic grafts (HAGs) implantation in patients with Marfan syndrome. There were 31 patients with Marfan syndrome and aortic aneurysm who were operated on between 1980 and 1996. Aortic dissection was diagnosed in 14 patients, DeBakey Type I in six patients and Type II in eight patients. Four patients had to be operated urgently in cardiogenic shock with cardiac tamponade. Sealing up and reinforcement with strip of felt or Gore-Tex has been applied in 22 patients. The surgical modifications mentioned above have been applied since 1987 in all patients with the diameter of the aortic ring exceeding 30 mm or with active infective endocarditis or during reoperation. In 16 patients the space between the aortic homograft and patients own aortic wall was joined to the right atrial auricle. Patients were followed up for 12-179 months (average: 94.6 +/- 499). Three patients died in the early postoperative period and four patients died in the late postoperative period. Rethoracotomy because of bleeding complications was necessary in five patients. HAG damage was responsible for six other reoperations-new HAGs have been implanted in three patients and artificial prostheses were implanted in the other three patients. In the late follow-up period significant improvement in cardiac performance was observed in 24 patients (NYHA I or II). Survival probability of 15 years for the whole group was 80%. The lowest survival probability has been shown in the group of patients with DeBakey Type I aortic dissection (35% survived 15 years after operation). Echocardiographic follow-up has shown that the pressure gradient in HAG was low (7.4 +/- 6.2 mmHg). Only in two patients did the HAG gradient exceeded 20 mmHg. There were no significant differences concerning aortic ring diameters, dimensions of HAG and echocardiographic parameters between the group with surgical modifications, i.e. sealing up and reinforcement with strip of felt or Gore-Tex applied and the group in which these modifications were not applied. Homogenic aortic graft implantation as a method of surgical treatment of aortic aneurysm in patients with Marfan syndrome avoids postoperative anticoagulation, results in substantial improvement of cardiac performance and prolongs life. Surgical treatment should be considered in asymptomatic patients with large aneurysms (exceeding 55-65 mm) in patients with Marfan syndrome because there is a high risk of death in this group of patients in the case of dissection.