During the period November 1969 to June 1972, a frame-supported autologous fascia lata graft was implanted in 71 consecutive patients with surgically treated aortic valve disease at the Department of Thoracic & Cardiovascular Surgery, University Hospital, Uppsala. The follow-up period was between 1 and 4 years. Eleven patients died within 28 days of the operation (16%) and 13 after discharge from hospital (18%); the cumulative mortality was thus 34%. Forty-five percent of the patients who died had associated cardiovascular or other diseases. The causes of death were infection (10), myocardial failure (6), myocardial infarction (3), cerebral damage (3), and intraoperative aortic dissection from the cannulation site (2). The majority of the deaths (88%) occurred within 6 months and all within 13 1/2 months after operation. Two fascia lata valves were removed because of endocarditis 23 and 26 months, respectively, after operation. Two valves were also removed on account of mechanical malfunction. The remaining 44 patients with fascia lata valves had returned to work. No embolic complications occurred, despite the fact that only patients with a concomitant prosthetic mitral valve or atrial fibrillation received anticoagulatant treatment. Haemodynamic studies of the valve in vitro and pressure measurements during the operation showed that the valve had a low primary systolic peak gradient of 0-16 mmHg. Certain modifications in the construction aimed at improving the haemodynamic properties of the valve are discussed. Increased stringency in the sterility precautions during the valve construction procedure may have contributed to the fact that early endocarditis, which is a serious complication, did not occur in any of the last 43 patients. As yet the observation time is too short to judge, however, to what extent susceptibility to infection and possible late changes of the valve can affect its function.