Extracorporeal Membrane Oxygenation (ECMO) is a critical life-saving intervention for children with severe cardiac failure. This chapter provides a comprehensive overview of cardiac ECMO, covering its historical development, indications, cannulation techniques, management strategies, and patient outcomes. Veno-arterial (VA) ECMO remains the predominant modality in pediatric cardiac cases, offering both circulatory and respiratory support. The decision to initiate ECMO is guided by clinical indicators such as inadequate end-organ perfusion, severe myocardial dysfunction, and failure to wean from cardiopulmonary bypass. Key aspects of ECMO management include hemodynamic optimization, anticoagulation strategies, monitoring for complications such as bleeding and neurologic injury, and the importance of myocardial recovery. Special considerations are given to single-ventricle physiology, residual cardiac lesions, and ECMO support in heart transplantation. The weaning and decannulation process requires careful evaluation of cardiac function and readiness for independent circulation. Despite advancements in ECMO technology and clinical protocols, survival rates in pediatric cardiac ECMO have not significantly improved over the past decade, emphasizing the need for better patient selection, anticoagulation strategies, and innovative circuit technologies. Emerging research into bioactive circuit coatings and alternative anticoagulants holds promise for improving ECMO outcomes. Future efforts should focus on optimizing patient selection criteria and refining management strategies to enhance survival and long-term neurological outcomes in this vulnerable population.