Sepsis-associated encephalopathy is a common but neglected clinical symptom of systemic inflammatory reaction in the early phase. The clinical spectrum of diffuse cerebral dysfunction induced by systemic sepsis--sepsis-associated encephalopathy according to the new terms--varies from transient, reversible encephalopathy, to severe irreversible brain damage. The aim of the present publication is to summarize the pathophysiology, frequent symptoms and possible treatments of the disease based on international and Hungarian articles on this topic. We want to emphasize the importance of monitoring the patient's mental status due to the fact that consciousness' disturbance of different severity is an early warning sign of sepsis, so it has high clinical significance.