Preservation of viable myocardium is the primary goal of coronary artery surgery. Our total experience with coronary artery bypass grafting is 1,612 patients, operated upon from March 13, 1969, through Jan. 31, 1975 (2.85 per cent over-all mortality rate). Four hundred thirteen patients were operated upon on an emergency basis. Of this group, 96 were having acute myocardial infarctions and 317 were in the preinfarction syndrome. Emergency coronary artery bypass surgery was performed with 5 deaths (5.2 per cent) in the acute myocardial infarction group and 4 deaths in the preinfarction group (1.26 per cent). These patients had a much lower mortality rate than that of medically treated patients in the acute myocardial infarction group. Postoperative catheterization studies on the acute myocardial infarction group showed a 96 per cent rate of primary graft patency. Follow-up studies through 3 years, 10 months show only 1 late death (4 months after the operation). The in-hospital and the first year mortality rates in a medically treated group with acute myocardial infarction were compared with the surgically treated group. The result was a mortality rate of 30 per cent with medical treatment and 6.3 per cent with surgical treatment. Actuarial analysis demonstrated a greater than 20 per cent difference in mortality rate at 1 year, in favor of surgical treatment. The lower surgical mortality coupled with the early and late clinical results prove that emergency coronary bypass is superior therapy in selected patients with acute myocardial infarction.