To evaluate the long-term cumulative incidence of ≥ moderate pulmonary regurgitation (PR) and re-intervention following balloon pulmonary valvuloplasty (BPV). While BPV for pulmonary valve stenosis (PS) relieves obstruction acutely, long-term outcomes are not well documented. Between 1982 and 2002, 211 patients had BPV for isolated PS. Follow-up data were available for 103 patients. Cumulative incidence of ≥ moderate PR and re-intervention was evaluated and risk factors for ≥ moderate PR assessed in univariate and multivariable analyses. Median age at BPV was 0.7years (range 1day-42.2years); peak catheter gradient was 65mmHg (range 31-169mmHg); 23% had critical PS. Sixty-two patients had a recent echocardiogram with median follow-up 15.1years (range 10.1-26.3years); 60% had ≥ moderate PR. Three patients had pulmonary valve replacement following BPV due to symptomatic severe PR. In univariate analysis, critical PS, younger age, smaller BSA, and smaller pulmonary annulus at the time of BPV, as well as greater baseline PS gradient by catheterization, were associated with ≥ moderate PR (all p<0.05). In multivariable analysis, only BSA<0.3m2 was independently associated with ≥ moderate PR (adjusted odds ratio 6.4, 95% confidence interval 1.2-33.6). In the largest study to date of > 10-year outcomes following BPV, 60% of patients with available follow-up data developed ≥ moderate PR. Few patients had pulmonary valve replacement. Patients with lower BSA at the time of BPV were more likely to have greater PR at late follow-up.