This is a report of early clinical experience with an autologous tissue cardiac valve, which demonstrates the feasibility of making a bioprosthesis in the operating room in 10 minutes at the time of the valve replacement operation. There were 30 implant patients (18 men, 12 women), with ages ranging from 32 to 83 years. Diagnoses included calcified aortic stenosis (n = 16), pure aortic insufficiency (n = 9), and mixed aortic stenosis and insufficiency (n = 5). Associated diagnoses have included chronic renal failure treated with dialysis (n = 1), coronary artery disease requiring concomitant coronary bypass (n = 1), ascending aortic aneurysm requiring resection (n = 3), and mitral insufficiency requiring concomitant mitral valvuloplasty (n = 2). All of the valve replacements were in the aortic position. These implanted patients are being followed up carefully according to the protocol that requires examination every 6 months for the first year and every 12 months subsequently. No patient has been lost to follow-up. Twenty-seven patients are alive and well from 1 to 22 months postoperatively. There were three deaths: two perioperative deaths (one perivalvular leak and one hemorrhage) and one infective endocarditis 1.3 years after valve replacement. All surviving patients were followed up by echocardiographic examination (mean gradient, 15.5 +/- 6.8 mm Hg at 1 year). In conclusion, the feasibility of this method and concept has been demonstrated with implants in 30 patients. The validity of the technique will be judged by clinical results and experiences in children.