Acute liver failure (ALF) is a rare life-threatening condition characterized by acute liver injury, hepatic encephalopathy and prolonged prothrombin time (PV/INR .1.5). It causes massive necrosis of hepatocytes which leads to a serious disturbance of liver function that can lead to multi-organ failure and death. It is extremely important to diagnose the ALF in due time, otherwise the prognosis of the disease is very poor with a high mortality rate. Patients require intensive treatment in intensive care units preferably in an institution where it is possible to perform a liver transplant as the ultimate form of therapy. ALF can be divided into 3 categories according to the time of onset: hyperacute - less than 7 days; acute – from 7 to 21 days; and subacute - 21 days to 26 weeks. The etiology of acute liver failure is crucial for the choice of therapy for the patient. The leading causes are acetaminophen overdose (paracetamol) and viral hepatitis. The diagnosis of acute liver failure should be suspected in every patient with jaundice, pain in the upper right quadrant and changes in neurological status that occurred within 26 weeks. Diagnosis of acute liver failure is based on thorough anamnesis and physical status and fulfilled with laboratory diagnosis, necessary imaging methods and pathohistological analysis of the liver sample. The main feature of acute liver failure therapy is the implementation of treatment in the appropriate institution with the crucial possibility of conducting liver transplantation as the ultimate form of therapy, monitoring the patient and providing nutritional support. Only 40% of patients with acute liver failure will recover spontaneously while other patients will need a liver transplant as a form of treatment. It is necessary to distinguish patients whose only option for recovery is liver transplantation from patients who have the possibility of spontaneous recovery because in this way we avoid unnecessary use of lifelong immunosuppressive therapy and complications of the surgical procedure in people who do not need liver transplantation. Numerous complications of the disease are possible, such as hemodynamic instability, bleeding, infections, metabolic disorders, neurological disorders, acute renal failure, and respiratory disorders. The prognosis of patients suffering from ALF is improving over time due to constant improvements in the treatment of the underlying disease and its complications and due to the research of new types of therapeutic methods.