Metabolic encephalopathy (ME) represents a syndrome of temporary or permanent disturbance of brain functions that occurs in different diseases and varies in clinical presentation. It can be manifested in a range from very mild mental disorders to deep coma and death. Clinically, it is characterized by a variety of psychiatric and neurological symptoms and signs. The most common causes of ME are: hypoxia, ischemia, systemic diseases and toxic agents. ME is the most frequent in elderly people who have previously been exhausted by chronic illnesses and prolonged stay in bed. ME is a very common complication in patients treated in intensive care units. Treatment and prognosis of the disease are varied and depend on aetiology, as well as on the type and severity of clinical presentation. Mortality of patients with septic encephalopathy ranges from 16-65%, while the one-year survival of patients with encephalopathy and liver cirrhosis is less than 50%.