Between 1984 and December 1990 balloon valvuloplasty for valvular pulmonary stenosis was planned and performed in 92 children over 6 months of age (range 0.8–17.9 years). Valvuloplasty decreased the invasively determined peak systolic gradient from 61±34 (mean±SD) to 27±20 mmHg (P <0.0001 At follow-up cardiac catheterization, performed in 22 patients after 13±5 months, the gradient was 22±23 mmHg (ns). Initially the continuous wave Doppler gradient decreased from 61±23 to 26±12 mmHg (P <0.0001). It then remained unchanged both at early follow-up after 0.6±0.3 years, being 23±12 mmHg and at long-term follow-up after 3±1.7 years (21±10 mmHg, ns). In the 41 patients treated before the end of 1986 the residual continuous wave Doppler gradient at long-term follow-up after 5.1±0.8 years was 21 ± 10 mmHg. Mild pulmonary regurgitation was present in 77% of the patients at early follow-up and in 83% at the last follow-up. Right ventricular hypertrophy on the electrocardiogram was present in 83% of the children before valvuloplasty. At early follow-up it had decreased to 44% with afurther decrease to 24% at the last follow-up. Comparison of patients with initial invasive systolic gradients greater and smaller than 50 mmHg revealed no differences between either group with regard to the continuous wave Doppler gradient at last follow-up, the incidence of pulmonary regurgitation and the occurrence of significant complications. Pulmonary balloon valvuloplasty can be safely and successfully performed in children over 6 months of age. Restenosis is rare and the relief of the gradient persists in the long-term. Pulmonary regurgitation remains mild. The electrocardiogram is of little value in the follow-up of these patients.