Percutaneous pulmonary balloon valvotomy using one balloon or more in sequential approach was attempted in 9 no selected neonates with critical pulmonary valve stenosis between March 1985 and October 1990 (mean age 10 + 8.6 days). The procedure was successful in seven of them (78%) in whom with a 1.22 + 0.2 balloon/annulus ratio the right ventricular systolic pressure decreased from 96 to 45 mmHg (p < 0.001), the transvalvular gradient from 65 to 23 mmHg (p < 0.001); and the systemic oxygen saturation increased from 69 to 86% (p < 0.001). In one patient the valve was not crossed. Two patients underwent surgery because unsuccessful balloon valvotomy result in the immediate and mid term period: hypoplastic right ventricle in one, and inferior vena cava thrombosis that prevent a second dilation in the other respectively. The mid term follow up showed a 62% (5/8) of successful result. Although the complex methodology and complications are not uncommon, the balloon pulmonary valvotomy is a safely and effective therapy for neonates with critical pulmonary stenosis.