Cardiac catheterization is a common cause of arterial thrombosis in children. Besides heparin therapy, fibrinolysis plays a major role in the therapeutic approaches to arterial thrombosis while surgery is rarely performed in pediatric patients. We report on a 19 month old patient with tetralogy of fallot, who developed thrombosis of the right femoral artery after a retrograde interventional cardiac catheterization. We performed an antegrade balloon angioplasty of his thrombosed femoral artery using a transvenous, transcardial approach via a ventricular septal defect. There were no complications. Doppler sonography showed no residual stenosis after 4 months.