Background and aims of the study: Mechanical valves require anticoagulation therapy, and bioprostheses may need reoperation due to structural valvular deterioration (SVD). In older patients, the rate of SVD seems to be lower than in younger patients. The aim of this study was to evaluate a 12-year clinical experience of the Carpentier-Edwards pericardial bioprosthesis in the aortic position in patients over 60 years of age. Methods: A total of 652 patients over 60 years old (453 men, 199 women; mean age 72.2±6.7 years) underwent isolated aortic valve replacement with the Carpentier-Edwards pericardial bioprosthesis in our institution between July 1984 and December 1995. The main indication for valve replacement was idiopathic calcific stenosis in 476 cases (75%), while dystrophic insufficiency was present in 124 of the cases (19%). Other conditions were rheumatic, congenital, prosthetic valve dysfunction and endocarditis. All patients, except one, were followed up for an average of 4.36 years after surgery resulting in a total follow up period of 2, 802 patient-years (pt-yr). Results: The operative mortality rate was 3.1% (20/652) including 138 late deaths. Thirty patients died of valve-related causes (14 sudden deaths, 11 thromboembolisms, 3 prosthetic valve endocarditises (PVE) and 2 bleeding events). Twelve years after surgery, the actuarial rate of freedom from valve-related death was 76±24%. Valve-related complications included 37 thromboembolic episodes (1.4%/pt-yr), 9 bleeding events (0.4%/pt-yr), 14 PVEs (0.4%/pt-yr), 2 structural valve failures (0.07%/pt-yr) and 8 reoperations (0.3%/pt-yr). Twelve years after surgery, freedom from thromboembolism was 80±12%, freedom from bleeding events was 96±3%, freedom from PVE was 96±2%, freedom from structural valve failures was 98±2% and freedom from reoperation was 96±4%. Conclusion: With a low rate of structural valve failure 12 years after surgery and a good clinical performance, the Carpentier-Edwards pericardial bioprosthesis is a reliable alternative for patients over 60 years of age.