Abstract Hypoplastic left heart syndrome is a rare congenital heart defect in which the left-sided heart structures are underdeveloped, such that the left ventricle is unable to support the systemic circulation. It is almost always lethal without surgical treatment, and if left untreated would account for around 25–40% of neonatal cardiac deaths in the United Kingdom. Complex neonatal surgery to enable the right ventricle to support the circulation (the Norwood Procedure) has transformed management of the condition, but requires three staged procedures during early childhood. Management of these patients into adulthood will offer new challenges. Transplantation for this condition remains rare, and is reserved for those in which conventional treatment has failed. In this review article, we discuss epidemiology, genetics, morphology, pathophysiology, prenatal diagnosis, modes of clinical presentation, and management strategies in this challenging condition.