Hypoplastic left heart syndrome (HLHS) is the most common functional single ventricle congenital cardiac defect. This syndrome is characterised by a functional single right ventricle and systemic outflow obstruction. The systemic and pulmonary circulations compete for cardiac output with a resultant precarious balance among systemic, pulmonary and coronary blood flows. A once fatal diagnosis, advances in operative and perioperative care have resulted in a dramatic improvement in survival. The preoperative management of neonates with HLHS is based predominately on clinical experience and extrapolated data from the postoperative literature. Management focuses on maintaining patency of the systemic outflow, balancing the pulmonary and systemic blood flows, and preserving the function of a single right ventricle to maximise oxygen delivery to the tissues. This paper reviews the available therapies for the preoperative management of HLHS.