Background: According to the Japanese Circulation Society guidelines, a bioprosthesis is recommended for aortic valve replacement (AVR) in patients aged ≥65 years who have no risk factors for thromboembolism. There are few data, however, regarding the actual durability of bioprosthetic valves in Japanese patients. The purpose of this study was to assess the long-term durability of Carpentier-Edwards pericardial (CEP) valves in Japanese AVR patients, and to assess the risk factors for reoperation due to structural valve deterioration (SVD). Methods and Results: From 1986 to 2001, a total of 591 patients underwent AVR with CEP valves in 9 hospitals. Of these, 574 patients (mean age, 71.9±8.5 years) were analyzed in this study. There were 26 in-hospital deaths (4.5%). The 10-year follow-up rate was 82.6% and the median follow-up time was 9.2 years. Freedom from reoperation due to SVD was 99.5%, 96.7%, and 87.5% at 5, 10, and 15 years, respectively. Factors that raised the risk of reoperation due to SVD included younger age at operation and history of prior operation. In patients aged ≥65 years, freedom from reoperation due to SVD was 94.4% at 15 years. Conclusions: The durability of CEP valves in patients with AVR was excellent, especially in elderly patients. Thus, it seems appropriate to follow the current Japanese Circulation Society recommendations for the use of bioprosthetic valves.  (Circ J 2014; 78: 882–889)