BACKGROUND. The aim of our study was to evaluate the incidence of early postoperative cognitive decline (POCD) and determine perioperative risk factors as well as the impact of asymptomatic cerebral vascular lesion on the development of neurocognitive complications. MATERIALS AND METHODS. A total of 127 consecutive adult patients undergoing on-pump coronary artery bypass grafting were studied. Neuropsychological testing was performed the day before surgery and 7-9 days after operation. Stepwise logistic regression analysis determined independent predictors of POCD. RESULTS. The incidence of postoperative cognitive decline was 46% (n=59). Patients in the POCD group were older (P=0.04) and had an increased prevalence of asymptomatic carotid artery stenosis (P=0.0001). POCD was associated with longer time in surgery (P=0.018), inotropic support intraoperativelly (P=0.02) and during postoperative period (P=0.008). Patients in the POCD group had an increased incidence of postoperative bleeding (P=0.037), delirium (P=0.016) and stayed in hospital for a longer period (P=0.007). Age of more than 65 years (OR, 2.7), asymptomatic carotid artery stenosis of more than 50% (OR, 26.89), duration of surgery of more than 4 hours (OR, 4.08), postoperative mechanical ventilation of more than 6 hours (OR, 3.33), and stay in an intensive care unit for more than 3 days (OR, 3.38) were significant independent predictors of cognitive decline. CONCLUSIONS. Increased age, preoperative prevalence of craniocervical atherosclerotic lesions, longer time in surgery, longer stay in an intensive care unit and mechanical ventilation time were found to be the risk factors for developing postoperative cognitive decline.