Coronary artery bypass grafting (CABG) has been widely used for the treatment of patients with coronary artery disease. Patients with low ejection fraction (EF) are at a higher risk for postoperative complications and mortality. Our objective was to assess the effect of low EF on clinical outcomes of CABG. We analyzed 1156 patients, who have undergone CABG in our department between 2002 - 2009 years. Patients were stratified into I of II EF groups: I Group - EF< or = 35% (100 patients) and II Group - EF > 35 % (1056 patients). EF was estimated by left ventriculography preoperatively and by echocardiography postoperatively. Surgical treatment was carried out only in cases, where the target coronary arteries were of relatively good diameter, to achieve complete revascularization. Group I experienced a higher incidence of postoperative respiratory failure. intraoperative mortality - 0, postoperative mortality- 4 (4%), reoperation - 0. Postoperative survival data were available for 73 patients. These data were obtained from our own medical records. This follow up manifested, that long term survival was 95, 8%. EF significant improvement (EF >40%) was in 82% and EF unimportant improvement only in 13% of cases. Multivariate analysis showed previous myocardial infarction, congestive heart failure, age, diabetes mellitus and arterial hypertension as independent significant predictors of in-hospital complications. Patients with low EF have higher incidence of postoperative complications, as well as preoperative sickness and risk factors, than patients with normal EF. Therefore CABG remains a viable option in selected patients with low EF. In patients with compromised left ventricular function and low EF, caused by atherosclerotic cardiosclerosis, lyal factors of CABG are angina and qualitative coronary arteries.