Patients with myocardial infarction (MI) who have out-of-hospital cardiac arrest and cardiogenic shock have a high mortality rate. Although intra-aortic balloon counterpulsation is frequently used in patients with cardiogenic shock, it does not provide complete hemodynamic support. We report 2 cases in which extracorporeal membrane oxygenation was instituted emergently in the cardiac catheterization laboratory in patients with MI and cardiac arrest who underwent percutaneous coronary intervention and who were hemodynamically unstable despite inotropic agents and intraaortic balloon counterpulsation.