Three patients under two years of age are described with unusual fistulas involving the brachiocephalic arteries and the innominate vein or the superior vena cava. Two patients were asymptomatic, and one newborn was cyanotic and in congestive failure. This unusual presentation has only rarely been reported in thoracic arteriovenous malformations. Two of the three patients underwent successful surgical repair. Two-dimensional echocardiography aids in the evaluation of these patients, but cardiac catheterization and angiography are indispensable diagnostic techniques for documenting the extent and location of these lesions and thus guiding proper therapy.