Case Report : A four-month-old boy with transposition of the great arteries with ventricular septal defect and pulmonary stenosis and multiple aortopulmonary collateral arteries, received a right modified Blalock-Taussig shunt (3.5 mm Gore-tex graft) and clippings of multiple aortopulmonary collateral arteries during early neonatal period. Due to the exacerbation of cyanosis for several days, the baby visited this center. On admission there was no continuous murmur, and the flow through the shunt could not be identified by color Doppler echocardiography. At catheterization a right innominate arteriogram confirmed a complete occlusion of the Gore-tex tube of modified Blalock-Taussig shunt at the proximal part. From the right innominate artery, an 0.014 inch guidewire was used to perforate the occluding thrombus using rapid wire manipulation. Clot disruption using staged balloon angioplasty of the shunt was performed with 2 mm and 4 mm diameter coronary balloon. After angioplasty the oxygen saturation increased from 55% to 80%. The patient was treated with intravenous heparin and urokinase infusion for the further thrombolysis and to prevent re-thrombosis. Before discharge, the color Doppler echocardiography eight days later showed a widely patent shunt. Conclusion : Balloon angioplasty using coronary balloon catheter is effective in restoration of the patency of occluded Blalock-Taussig shunt.