The results with medical treatment of the patient with coronary artery disease and marked impairment of left ventricular function have been poor. Of 79 patients deemed operable with an ejection fraction of 0.2 or less, only 17 (22 per cent) were alive according to an acturial curve 5 years later. We believed that surgery might offer a better outlook for these critically ill patients. Therefore, since 1969, 140 patients with an injection fraction of 0.2 or less were treated by myocardial revascularization alone, with 31 hospital deaths. Actuarial curve reveals that at 6 years, 59 per cent of the surgically treated patients are alive, and only 22 per cent treated medically are alive at 5 years. It is concluded that if the operative mortality rate is low enough, surgery enhances the survival of patients who have drastic impairment of left ventricular function. These patients are significantly improved clinically.