Extra Corporeal Membrane Oxygenation (ECMO) is a supportive therapy used to provide cardiac support with or without respiratory support in the event of cardiopulmonary failure. The two main types of ECMO are Veno-arterial ECMO (VA-ECMO) and Veno-venous ECMO (VV-ECMO). The use of ECMO in cardiac surgery has been established in cases of post-cardiotomy cardiogenic shock which is refractory to conventional therapy with inotropes and intra-aortic balloon pulsation support. Survival for this, otherwise, fatal condition has been shown to be improving through the use of ECMO. However, the decision and timing to initiate ECMO therapy remains selective and is dependent on a range of factors such as patient factor, clinician’s judgement, meaning there is no consistent and solid ground regarding the timing of ECMO initiation. This article will provide an extensive review of ECMO indications, contraindications, complications and outcomes to analyse the survival benefit of ECMO following cardiac surgery.