Extracorporeal membrane oxygenation (ECMO) is used for both cardiac and pulmonary failure when conventional measures are no longer substantial in supporting life. ECMO is not a permanent device. It is used as a temporary measure to allow the lungs and heart, as well as other organs to recover. If recovery is not possible, it may also be used as a bridge to a more permanent device such as the left ventricular assist device or heart or lung transplantation. This is a detailed description of the differences between venovenous ECMO and venoarterial ECMO and the nursing care that is associated with the two. A case study of a 37-year-old man on ECMO due to cardiogenic shock is included.