The aim of this study was to evaluate the early results of interventional balloon dilatation of stenotic bovine jugular vein (BJV) grafts implanted for reconstruction of the right ventricular outflow tract (RVOT) in children. METHODS: From May 2001 to December 2005, 153 BJV grafts were implanted in children in our institution. An average of 16.9 (7.6-41.1) months after implantation, 17 balloon dilatations in a significant stenosis proximal (n = 1), distal anastomosis (n = 8), BJV valve (n = 3), or at multiple sites (n = 5) were performed in 15 children (male:female = 9:6) with a mean age of 3.9 (0.8-13.0) years. Balloon diameter was 75-133.3% (mean 100.3) of the original BJV size. Mean follow-up was 8.8 (2 days to 22.8 months) months. RESULTS: In 10 interventions (58.8%) the instantaneous peak gradient was reduced below 50 mmHg. A balloon diameter > or =100% of the original BJV size correlated significantly with a successful intervention. No major complications, two minor (nonobstructive floating membranes at the dilatation site and one septicemia) occurred afterward. Freedom from reintervention after 6 months was 58.2% for all, 77.8% for dilatations of the proximal anastomosis and mixed stenotic lesions, and 33.3% for the distal anastomosis. CONCLUSION: Balloon dilatation of stenotic BJV grafts is safe and can significantly reduce the pressure gradient in two-thirds of interventions. Balloon diameters above the original graft size should be aimed for. The most frequent stenosis of the distal anastomosis tends to renarrow early after dilatation. Nevertheless, balloon dilatation should be considered in nearly every stenotic graft to gain time until a surgical or interventional graft exchange.