Relevance. The problem of purulent postoperative septic infection (the hospital acquired infection or HAI) is still one of the main cause of fatal outcomes of patients in cardiac hospitals, which demands significant material costs. The aim of the work is to evaluate the intensity of the epidemic process and risk factors for HAI among adults after various types of open heart surgery.Materials and methods. The study of medical records of 1540 patients over 18 years old, who underwent open heart surgery for the purpose of coronary artery bypass grafting (CABG), prosthetics of valves and elimination of aortic defects, was held. Typical and donozological forms of HAI were taken into account in accordance with the epidemiological standard definition of cases.Results. The incidence rates of typical and donozological forms of HAI in average was 39.6 and 72.7 per 1000 operations. The maximum incidence of HAI was detected after aortic surgery due to urinary tract infection (UTI) and hospital-acquired pneumonia.Conclusions. It was found that the increased incidence of UTI and hospital-acquired pneumonia after aortic surgery is contingent on a longer cardiosurgical operations and, accordingly, a longer stay of patients in the Department of anesthesia and resuscitation, accompanied by artificial ventilation and catheterization of the bladder, than in other cardiac operations