Extracorporeal cardiopulmonary resuscitation (ECPR) promises to be an important advance in the treatment of cardiac arrest. However, ECPR involves ethical challenges that should be addressed as it diffuses into practice. Benefits and risks are uncertain, so the evidence base needs to be further developed, at least through outcomes registries and potentially with randomized trials. To inform decision making, patients' preferences regarding ECPR should be obtained, both from the general population and from inpatients at risk for cardiac arrest. Fair and transparent appropriate use criteria should be developed and could be informed by economic analyses.