OBJECTIVE In a previous study, we identified factors affecting the durability of bioprosthetic valves in the pulmonary position following total repair of Tetralogy of Fallot (TOF). In this study, we aimed to identify factors affecting the durability of the bioprosthetic valve with regard to patient age and implanted valve size in order to guide valve choice in adolescent patients. METHODS We enrolled and analysed 108 cases of pulmonary valve replacement (PVR) with stented bioprosthetic valves in TOF patients between January 1998 and February 2014. Valvular dysfunction was defined as at least a moderate amount of pulmonary regurgitation or a peak pressure gradient of ≥40 mmHg on the most recent echocardiography. We analysed the effect of patient age and valve size on the durability of the bioprosthetic valve in the pulmonary position. RESULTS There were 2 early deaths; no late deaths were observed. The follow-up duration was 92.8 ± 44.5 months. The mean age at PVR was 19.3 ± 9.1 years. The mean valve size was 24.7 ± 1.8 mm. Whereas patients ≥20 years old showed no valvular dysfunction (i.e. 100% freedom from valvular dysfunction at 10 and 14 years), patients who were adolescents and children (<20 years) showed worse durability, regardless of the z-score of valve size (68.2% at 10 years and 24.7% at 14 years). Although a larger valve with a z-score of ≥2 was implanted, patients <20 years old did not exhibit good valvular durability. The results were particularly worse in patients <10 years old, with 66.7% freedom from valvular dysfunction at 6 years and 33.3% at 8 years, compared with patients within the age range of 10 to <20 years (75.1% at 10 years, and 20.5% at 14 years). CONCLUSIONS The durability of bioprosthetic valves in the pulmonary position was acceptable in patients aged ≥20 years, regardless of the z-score of valve size. However, patients who were children and adolescents did not show optimal durability of the bioprosthetic valve, irrespective of the z-score of valve size.