Emergency percutaneous cardiopulmonary bypass support was instituted in 11 patients in cardiac arrest refractory to conventional resuscitation measures. Emergency percutaneous cardiopulmonary bypass support was used in five patients in whom cardiac arrest occurred as a result of a complication in the cardiac catheterization laboratory (group 1) and in six other patients in cardiac arrest (group II). A 21F cannula and a 17F cannula were percutaneously inserted into the femoral vein and artery. Flow rates of 3 to 5 L/min were achieved with restoration of mean arterial pressure to 70 mm Hg (range 50 to 75). The status of all 11 patients was improved initially both clinically and hemodynamically with percutaneous cardiopulmonary bypass. Of the group II patients, three had anatomy unsuitable for percutaneous transluminal coronary angioplasty or coronary bypass grafting, could not be weaned from cardiopulmonary support, and died; three of these patients had coronary artery bypass grafting and two survived. All five group I patients underwent successful coronary bypass grafting and survived. Of the seven patients with anatomically correctable disease, all seven were discharged from the hospital. With conventional management nearly all seven of these patients would have died. Nine of 11 patients underwent a cardiac operation and seven of the nine survived. The operative mortality rate was 22% and the overall survival rate was 64%. At follow-up (mean 7 months), all seven patients are alive and six have resumed a normal and active life-style. In conclusion, emergency percutaneous cardiopulmonary bypass support is a powerful resuscitative tool that may stabilize the condition of patients in cardiogenic shock and cardiac arrest to allow for definitive intervention.