Postoperative cognitive dysfunction (POCD) is a frequent and clinically important consequence of surgical procedures. Mostly, it concerns memory and executive functions. POCD prevails in patients undergoing cardiac surgery, where it is also a risk factor for the occurrence of other complications. The aetiology of POCD is complicated and multi-factorial. Thus far, there is no evidence for a relationship between POCD and different surgical and anaesthetic techniques. However, such a correlation may exist in elderly patients. Risk factors of POCD include the clinical aspects of the underlying disease, age, early cognitive decline and alcohol abuse. It is important to further study the aetiopathology, methods of early detection and prevention of POCD. It may enable the implementation of therapeutic strategies that will improve patients’ cognitive functioning and therefore their quality of life.