At present, the treatment of a patient in acute liver failure is based upon scrupulous intensive care. In those patients whose condition deteriorates, emergency liver transplantation must be considered. There would be great benefit if it were possible to provide treatment which would stabilise the condition of a patient in acute liver failure. Thus, there is great incentive to develop a means of artificial liver support. Over many years, a considerable array of therapeutic strategies has been investigated. These can be considered in four main categories: plasma exchange, haemofiltration, extra-corporeal liver assist devices (ELAD), extra-corporeal liver perfusion (ECLP). Finally, the role of xenotransplantation is considered.