Study aim was to compare rates of perioperative complications of coronary bypass surgery in patients of various age groups and to analyze factors associated with their appearance. We retrospectively studied 2411 case histories of patients subjected to coronary artery bypass surgery between January 2006 and December 2009. According to their age at surgery patients were divided in 4 groups: <60 years (n=1555, mean age 53+/-6 years), 60-64 years (n=379, mean age 61+/-3 years), 65-69 years (n=335, mean age 67+/-2 years), >70 years (n=142, mean age 71+/-3 years). In older age groups hospital mortality and total number of complications were greater than in patients aged <60 years. Hospital mortality and rates of postoperative complications did not significantly differ between groups of patients aged 60-64, 65-69, and more or equal 70 years. Besides age the following factors were independently associated with hospital mortality: characteristics of extent of atherosclerosis (significant occlusive-stenotic lesions in arteries of lower extremities and extracranial arteries, history of stroke); lowering of left ventricular ejection fraction; and use of cardiopulmonary bypass.