Since December of 1980, 184 patients with evolving myocardial infarction (EMI) have undergone streptokinase infusion, with associated percutaneous transluminal coronary angioplasty (PTCA) in 68 patients. Emergency coronary bypass was deemed necessary in 24 of these patients. All 24 patients had severe triple-vessel disease and moderate to marked ventricular dysfunction, with eight (33%) requiring intra-aortic balloon pump (IABP) support for profound cardiac decompensation preoperatively. All 24 patients underwent immediate coronary bypass (average 4.1 grafts/patient), with four operative and two late deaths. Average postoperative blood loss was 1,453 ml, and average blood transfusion postoperatively was 8.2 units per patient. Thirteen patients had normal clotting studies immediately postoperatively, and only two patients developed frank coagulopathy (hyperfibrinolysis). Four patients required reexploration; two for coagulopathy, one for surgical bleeding, and one to rule out tamponade (negative). In those patients with EMI in whom streptokinase fails to result in adequate reperfusion, immediate emergency saphenous vein bypass grafting may be performed with reasonable morbidity and with acceptable hematologic consequences.