Progressive dilatation of the neoaortic root and reconstructed aortic arch is a serious complication after the Norwood procedure. There are no clear guidelines on the management of this complex anatomy in the setting of single ventricle physiology, and the surgical treatment of such an entity remains anecdotal. We describe a successful surgical repair in a 15-year-old girl presenting with a severely dilated neoaortic root and aortic arch causing compression and narrowing of the left pulmonary artery after successful three-stage palliation for hypoplastic left heart syndrome.