We review the validity of balloon occlusion aortography (BOA) on the basis of our personal experience with 18 patients with congenital heart disease (mean weight 4.55 g, including 8 neonates). Four of the 18 patients underwent aortic arch angiography using balloon occlusion of the descending aorta. Pulmonary angiography was also performed in 9 patients via a patent ductus arteriosus and in 3 patients via a Blalock-Taussig shunt. The remaining 2 patients underwent coronary arteriography by balloon occlusion of the ascending aorta. The information obtained was satisfactory in 17 of the 18 patients. However, in one patient with a double-outlet right ventricle and pulmonary stenosis, the pulmonary arteries were not clearly visualized because of dominant antegrade flow from the right ventricle. BOA is a safe and useful procedure which can be used to image the aortic arch, pulmonary artery, and coronary arteries in infants with congenital heart diseases. In children over 3 years of age, however, the balloon may not be able to occlude the appropriate site of the aorta, so selective angiography is required to obtain precise information.