Aortic arch aneurysm or pseudoaneurysm is a rare complication early after coarctation repair in the neonatal period. We report the case of a newborn with a ventricular septal defect and aortic coarctation with a hypoplastic aortic arch that developed a large aortic arch pseudoaneurysm following a radically extended end-to-end coarctation repair. Successful surgical correction of the pseudoaneurysm was performed.