BackgroundIsolated subclavian or brachiocephalic artery are uncommon aortic arch anomalies. Here we report the anatomy and histology of this disease. MethodsFour cases of congenital isolated subclavian or brachiocephalic artery in fetuses are described. ResultsWe identified one case of right aortic arch with isolated left subclavian artery associated with the tetralogy of Fallot, two cases of right aortic arch with isolated left brachiocephalic artery (one case with left retro-aortic brachiocephalic vein), and one case of left aortic arch with isolated right subclavian artery associated with coarctation of the aorta and cervical aortic arch. The proximal subclavian or brachiocephalic artery is arterial duct. ConclusionAortic arches with an isolated subclavian or brachiocephalic artery are often associated with the tetralogy of Fallot. It also can be associated with rare abnormalities such as left retro-aortic brachiocephalic vein or cervical aortic arch. Isolated LBA can be associated with microdeletion chromosome 22q11.