Emergency neonatal and paediatric cardiac surgery, although infrequent, remains among the most demanding areas of congenital cardiac care. This chapter reviews the principal indications and operative strategies for emergent intervention, focusing on conditions such as obstructed total anomalous pulmonary venous drainage, critical coarctation of the aorta refractory to prostaglandin therapy, simple transposition of the great arteries with inadequate mixing and anomalous left coronary artery from the pulmonary artery. The application of extra-corporeal membrane oxygenation is examined as a vital adjunct in perioperative stabilisation and postoperative support. The chapter also considers the evolving role of immediate post-natal surgery, facilitated by advances in foetal cardiac imaging and multidisciplinary perinatal planning. Emphasis is placed on the integration of timely diagnosis, surgical decision making and critical care optimisation in improving survival and functional outcomes. While these interventions are associated with substantial physiological and technical challenges, continuing progress in surgical technique, mechanical circulatory support and perioperative management has led to significant improvements in morbidity and mortality across this high-risk patient population.