Extracorporeal membrane oxygenation (ECMO) is a controversial means of life support, particularly in adults. Ongoing refinements in circuit technology and widening global experience have led to ECMO being applied to a broader group of conditions than acute respiratory failure and cardiogenic shock. Septicaemia is no longer viewed as a contraindication to ECMO. Acute respiratory distress syndrome and bacterial pneumonia are the most common conditions in sepsis that may require ECMO, although septic shock with refractory hypotension may also be an indication under certain circumstances. The last indication is generally more applicable in children than adults, because of differences in the cardiovascular response to severe sepsis seen across age groups. ECMO has a role as rescue therapy in patients with severe sepsis who would otherwise die of either hypoxaemia or inadequate cardiac output. This review describes the basic technique and application of ECMO in neonates, older children, and adults with sepsis.