From September, 1986 through December, 1989, 121 patients underwent aortic valve replacement with the Mitroflow pericardial valve. There were 70 males (58%) and 51 females (42%), with an average age of 71 years (range 50-85 years). Reported here are the long-term results from these patients. Concomitant cardiac procedures were performed in addition to aortic valve replacement in 38 patients (31%); Coronary artery revascularization in 27 patients (22%); 4 patients (3%) had combination aortic/mitral valve replacement; mitral valve reconstruction in 4 patients (3%) and 3 patients (2%) had other additional procedures. Following surgery, standard postoperative examinations were performed every six month for 2 years; then yearly thereafter. At these times valvular function assessed echocardiographically. Current follow-up extends to 7 years (mean = 5 years) for surviving patients. Postoperative mortality for all observation period is as follows: Early deaths (> or =30 days postop) = 6 patients (5%), late death (>30 days) = 18 patients (15%). Valve-related causes of death included cerebral insult (thromboembolism) in two patients (one 10 months, other 15 months postoperatively). Postoperative valve-related morbidity included prosthetic endocarditis (1 patient) one year postoperatively; degenerative prosthetic failure (1 patient) 27 months postop; cusp tear (1 patient) with minimal hemodynamic changes after four years. In the patients with endocarditis and failure, a second successful operation corrected the problem. Also, in two patients antithrombolitic therapy related hemor-rhage occurred (one 9 months, the second 11 months postoperatively). This therapy was a result of atrial fibrillation, and we do not recommended it. In conclusion, we find that the Mitroflow pericardial heart valve gives adequate long-term results, especially in elderly patients with a small aortic ring, with very satisfactory quality of life.