Limited data exists on long-term pulmonary valve function after the Ross procedure. This study sought to determine the long-term function of the pulmonary valve in 443 consecutive adult patients who underwent a Ross procedure.All 443 patients who underwent a Ross procedure between November 1992 and March 2018 were reviewed retrospectively. All underwent pulmonary valve replacement using a cryopreserved pulmonary allograft. Freedom from the study's outcomes were calculated using Kaplan Meier survival. Risk factors for valve failure were analyzed using Cox regression.Mean age at time of operation was 39 years (range 15-66 years). There was 1 (0.2%, 1/443) operative mortality. Nine patients required reintervention on the pulmonary allograft at a mean 6.1 years (range 1-12 years) after Ross procedure. Patients required pulmonary allograft reintervention for infective endocarditis (n=4), severe pulmonary stenosis (n=4) or severe pulmonary regurgitation (PR) (n=1). Freedom from pulmonary allograft reintervention was 98.9% (95%CI 97.1-99.6), 97.7% (95%CI 95.1-98.9), 96.6% (95%CI 93.3-98.3) and 96.6% (95%CI 93.3-98.3) at 5, 10, 15 and 20 years (Figure 1). Freedom from pulmonary allograft dysfunction (at least moderate PR and/or mean systolic gradient ≥ 25mmHg and/or reintervention) was 94.5% (95%CI 91.6-96.4), 88.1% (95%CI 83.6-91.4), 84.9% (95%CI 79.6-88.9) and 78.3% (95%CI 69.5-84.9) at 5, 10, 15 and 20 years. No risk factors were identified to influence pulmonary valve durability.The pulmonary valve allograft gives excellent long-term function when used in adults undergoing the Ross procedure. Reintervention on the pulmonary valve is rare and significant pulmonary allograft dysfunction is uncommon.