The ascending aorta or pulmonary trunk in congenital heart disease may dilate out of proportion to hemodynamic or morphogenetic expectations, may become aneurysmal, and may rupture. A bicuspid aortic valve and/or coarctation of the aorta are consistently associated with ascending aortic and para-coarctation medial abnormalities. Congenital heart diseases such as single ventricle, truncus arteriosus, transposition of the great arteries and tetralogy of Fallot are also associated with aortic medial abnormalities. Aortic regurgitation in unrepaired tetralogy of Fallot imposes volume overload on both ventricles. A significant subset of adults late after repair of tetralogy of Fallot exhibits progressive aortic root dilatation which may lead to regurgitation and predispose to dissection and rupture which can be fatal, and necessitating aortic valve and aortic root surgery. The aortic dilatation relates medial abnormalities coupled with previous long-standing volume overload of the ascending aorta. Risk factors for aortic dilatation and regurgitation in tetralogy of Fallot relate to specific hemodynamic abnormalities such as pulmonary atresia, right aortic arch and a history of an aorto-pulmonary shunt, and patient demographics such as male sex and the association of chromosome 22q11 deletion. There is no current consensus on β-blocker administration for limiting progressive dilatation of the aortic root in patients with congenital heart disease and repaired tetralogy of Fallot. Aortic root surgery should be considered for these patients and address aortic regurgitation and or prevent the risk of aortic dissection. Meticulous follow-up of the aortic root after repair, tetralogy of Fallot are thus recommended.