Data of 12 children (mean age = 3.1 yrs, range 0.4-11.1 yrs) with valvular pulmonary stenosis are reported. Balloon valvuloplasty was attempted for the treatment, first in the pediatric practice in our country. Echocardiography and cardiac catheterisation was used for the indication of the procedure and evaluation of the results. Strong correlation was found between the echocardiographic and haemodynamic data before (correlation coeff. = 0.9) and less strong after (correlation coeff. = 0.4) the procedure. As a result of the balloon dilatation the initial gradient of 62 mmHg (sd = +/- 17 mmHg) decreased to 20 mmHg (sd = +/- 10 mmHg) assessed by invasive technique. The difference is significant, p < 0.001. No major complication was observed. The procedure is recommended for widespread practice both in medical and financial sense.