Both in-hospital and out-of-hospital cardiac arrests are associated with a high mortality. In the past survival advantages for patients could be achieved by optimizing the chain of rescue and postresuscitation treatment; however, for patients with refractory cardiac arrest, there have so far been few promising treatment options. For selected patients with refractory cardiac arrest who do not achieve return of spontaneous circulation with conventional cardiopulmonary resuscitation (CPR), extracorporeal (e)CPR using venoarterial extracorporeal membrane oxygenation is an option to improve the probability of survival. This article describes the technical features, important aspects of treatment, and the current data situation on eCPR in patients with in-hospital or out-of-hospital cardiac arrest.