Acute liver failure (ALF) is uncommon and may be associated with a high mortality rate. Its aetiology shows considerable geographical variation, with viral hepatitis the most common worldwide, whilst acetaminophen (paracetamol) induced hepatotoxicity forms the most common precipitant in many developed countries. Its management requires meticulous intensive care and the effective management of haemodynamic, septic and cerebral complications. The early identification of patients unlikely to survive without emergency liver transplantation is important to maximize the possibility of an available graft. Survival in those patients who undergo transplantation may be in excess of 75%.