Abstract: Objective To summarize the immediate effects and the near and midterm followup results of transthoracic balloon valvuloplasty for newborns and infants with severe and critical pulmonary valve stenosis to find out an effective plan for onestop balloon valvuloplasty. Methods From March 2006 to March 2010, 32 patients including 23 males and 9 females with severe and critical pulmonary valve stenosis were treated in Fu Wai Hospital. Their age ranged from 5 days to 11 months (4.59±3.21 months). Weight of the patients ranged from 2.3 to 10.5 kg (6.48±2.05 kg). Dilatation was performed under general anesthesia with intubation and the guidance of echocardiography. During the follow-up period, all survivors had serial echocardiographic assessment to measure the transpulmonary pressure gradient (TPG) and the degree of pulmonary regurgitation. Results All operations were successful with no severe postoperative complications. Hemodynamic indexes were stable after operation with TPG lowered from from 82±27 mm Hg preoperatively to 23±12 mm Hg postoperatively (t=15.28, Plt;0.05). Only 4 patients had a TPG of more than 40 mm Hg on echocardiography before leaving the hospital. Tricuspid regurgitation was decreased significantly with 17 cases of nonregurgitation, 13 cases of light regurgitation and 2 cases of moderate regurgitation. Saturation of peripheral oxygen in all the patients increased to higher than 95%. Followup time ranged from 1 month to 4 years (16±11 months). The results of the follow-up were satisfying for all the patients. The average TPG was 17±10 mm Hg with only one above 40 mm Hg. Pulmonary valve regurgitation was found in 24 patients including 23 with light pulmonary regurgitation and 1 with moderate regurgitation. Conclusion Transthoracic balloon valvuloplasty for newborns and infants with severe and critical pulmonary valve stenosis is safe and effective.