Emergency percutaneous cardiopulmonary bypass support was instituted in 8 consecutive patients, ages 42 to 80 years, in cardiogenic shock for 30 to 180 minutes (mean 106) due to acute myocardial infarction. The location of the infarction was inferior in 4, anterior in 3 and lateral in 1. Four patients had a history of prior myocardial infarction. Two patients were in cardiac arrest; the remaining 6 had a mean blood pressure of 43 to 55 mm Hg before the bypass. Five had pulmonary capillary Wedge pressure greater than or equal to 20 mm Hg. One patient, with a right ventricular infarction, had a pulmonary wedge pressure of 10 mm Hg. Percutaneous insertion of 20Fr cannulas was carried out. Flow rates of 3.2 to 5.2 liters/min were achieved. Two patients in cardiac arrest regained consciousness while still in ventricular fibrillation or asystole. Left ventricular ejection fraction ranged from 17 to 40% (mean 32). One patient had left main, 4 had multivessel, and 4 had 1-vessel coronary disease. Seven patients had successful angioplasty of 15 of 16 lesions attempted, with all infarct-related vessels successfully dilated. One patient had lesions unsuitable for either bypass or angioplasty and died. Need for blood transfusion was the most frequent complication. One patient required surgical repair of the femoral artery. All 7 patients are alive at a mean follow-up of 8.2 months. It is concluded that cardiopulmonary bypass can be safely instituted percutaneously, hemodynamically stabilize patients in cardiogenic shock and facilitate emergency complex coronary angioplasty, which may be life-saving.