Objectives: Factors influencing results of balloon valvuloplasty (BVP) of pulmonary valve stenosis (PS) in children are investigated. Background: BVP has become the standard of care for PS, medium-term results are not uniform and depend on various preconditions. Methods: We analysed the medium-term results of BVP of PS in children in an observational, single centre study. Need for additional procedure was defined as outcome after initial BVP. Results: We included 143 children (83 female) at a median (IQR) age of 2.6 (0.26-9.24) months and body weight of 5 (3.4-8) kg at BVP with a follow-up of 5.04 (1.6-10.2) years. We used balloon size of 10 (9-14) mm and maximal balloon pressure of 4 (3.5-10) atm, resulting in balloon-to-pulmonary annulus ratio of 1.28 (1.2-1.4). Systolic pressure gradient of PS was reduced with BVP (43.5 mmHg vs. 14.0 mmHg, p < 0.001) and confirmed by echocardiography (68.0 mmHg vs. 25.0 mmHg, p < 0.001) day 1 post procedure. Pulmonary BVP with associated supravalvular PS resulted in a relevant reduction of systolic pressure gradient in 23 of 31 patients (74.2%). Early additional procedure was necessary in 14 patients (9.8%) after 0.2 (0.1-0.7) years due to residual PS (n = 13) and infective endocarditis (n = 1). Factors for additional procedures were associated supravalvular PS with a higher residual pressure gradient, but not genetic syndrome. During further follow-up of 5.04 (1.6-10.2) years no further additional procedures were needed. Conclusions: Pulmonary BVP of native pulmonary valve stenosis leads to excellent medium-term results, even in 3 of 4 infants with associated supravalvular obstruction sufficient pressure relief can be obtained.