Mechanical circulatory support has evolved markedly over recent years. ECMO (extra corporeal membrane oxygenation) is instituted for the management of life threatening pulmonary or cardiac failure (or both), when no other form of treatment has been or is likely to be successful. Most commonly, it is instituted in an emergency or urgent situation after failure of other treatment modalities. It is used as temporary support, usually awaiting recovery of organs, or can be used as a bridge to a more permanent device or cardiac transplantation. ECMO can be deployed in a veno-arterial configuration (either peripheral or central cannulation) for the treatment of cardiogenic shock. This is usually seen post-cardiotomy, post-heart transplant and in severe cardiac failure due to almost any other cause (e.g. cardiomyopathy, myocarditis, acute coronary syndrome with cardiogenic shock). Veno-venous ECMO is used for respiratory failure and usually involves peripheral cannulation using the femoral veins+/-internal jugular vein if required. The indications for veno-venous ECMO are respiratory failure, most commonly due to adult respiratory distress syndrome (ARDS), pneumonia, trauma or primary graft failure following lung transplantation. ECMO is also used for neonatal and paediatric respiratory support. Its use in premature neonates is the mainstay of treatment for immature lungs and insufficient surfactant. In this review, the technical aspects of ECMO cannulation, maintenance and weaning are outlined. Complication rates and outcomes are reviewed and our experience at The Epworth Hospital is summarized.