The study aim was to compare the durability and risk of reoperation in patients undergoing isolated aortic valve replacement porcine Carpentier Edwards (CE; n = 94) or Mitroflow (M; n = 118) pericardial valves. Between groups, only prosthesis size differed, with small-sized valves used more frequently in the M group. Risk of structural valvular dysfunction (SVD) was 2.3% per patient-year (pt-yr) in CE valves, and 5.4 per pt-yr in M valves. Freedom from SVD was 100%, 87 ± 4% and 63 ± 8% at 5, 10 and 15 years for CE valves, and 96 ± 2%, 56 ± 7% and 5 ± 4% for M valves. Freedom of reoperation was 98 ± 1%, 83 ± 5% and 76 ± 7% at 5, 10 and 15 years respectively for CE valves, and 94 ± 2%, 55 ± 7% and 11 ± 9% for M valves. Despite the high number of valve-related reoperations, survival at 5, 10 and 15 years was not affected in M valve patients. Multivariate analysis showed that age and valve type were the two main risk factors for SVD and reoperation; the latter factor had no impact on survival. To conclude, in patients aged <75 years, porcine bioprostheses offer superior results to their pericardial counterpart for valve replacement. However, in patients aged > 75 years, both bioprostheses show equivalent durability, despite post-implantation tissue changes in the former material.