Hypoplastic left heart syndrome (HLHS) is characterized by underdevelopment of the left ventricle and its outflow tract. Prenatal diagnosis of this congenital heart disease is crucial, as it contributes to 23% of cardiac deaths in the neonatal period. When not diagnosed in the prenatal period, it causes decompensated postnatal hemodynamics with clinical signs of low cardiac output when the ductus arteriosus begins to close. The aim of this chapter was to provide tools for the diagnosis of left heart anomalies and its outflow tract obstructive malformations with a focus on the main three-dimensional sonographic features that can be used in the prenatal diagnosis of HLHS, coarctation of the aorta, and aortic arch interruption.