Background: Postoperative cognitive dysfunction (POCD) represents a decrease of cognitive abilities (memory, learning, concentration), which develops in the postoperative period after a variable amount of time (days or weeks). Today, the pathogenesis of the POCD development is not fully known. Literature suggests multiple possible mechanisms of POCD development. Certainly, the neuro-inflammatory effect (generated by the surgery itself) from the cortical zones responsible for learning and memory, is one of the phenomena frequently noted in these patients. This article is a narrative synthesis of literature on postoperative cognitive dysfunction – a quite spread phenomenon found in patients during postoperative care. We described suggested theories and the pathophysiological mechanisms involved in the development of this clinical condition. Its incidence according to different types of surgery is presented. We reviewed the available tools for identification and qualitative assessment of postoperative cognitive dysfunction, including biomarkers. Also, we discuss the risk factors for postoperative cognitive dysfunction and their role in clinical decision making process. Conclusions: Postoperative cognitive dysfunction is a common complication after the surgery. It occurs in frail patients or in individuals presenting general risk factors. It looks like there is a genetic predisposition for the development of postoperative cognitive dysfunction. Patients at risk of postoperative cognitive dysfunction can be identified by neurocognitive testing tools.