Cognitive dysfunctions are relatively common in postoperative and critically ill patients. This complication not only compromises recovery after surgery, but, if persistent, it minimizes and compromises surgery itself. Risk factors of postoperative cognitive disorders can be divided into age and comorbidity dependent, and those related to anesthesia and surgery. Cardiovascular, orthopedic and urologic surgery carries high risk of postoperative cognitive dysfunction. It can also occur in other types of surgical treatment, especially in elderly. Among risk factors of cognitive disorders, associated with comorbidity, underlying psychiatric and neurological disorders, substance abuse and conditions with elevation of intracranial pressure are in the first place in postoperative patients. Preoperative and perioperative predisposing conditions for cognitive dysfunction and their incidence were described in our paper. These are: geriatric patients, patients with substance abuse, preexisting psychiatric or cognitive disorders, neurologic disease with high intracranial pressure, cerebrovascular insufficiency, epilepsia, preeclampsia, acute intermittent porphyria, operation type, brain hypoxia, changes in blood glucose level, electrolyte imbalance, anesthetic agents, adjuvant medication and intraoperative awareness. For each of these factors, evaluation, prevention and treatment strategies were suggested, with special regard on anesthetic technique.