The etiology of acute liver failure in patients without pre-existing liver disease varies depending on geographical location. In the United Kingdom, acetaminophen toxicity remains the most common cause while worldwide, viral hepatitis B is the most prevalence cause. The management of patients with acute liver failure requires the application of good basic intensive care - recently, the advent of liver transplantation has widened the therapeutic options available. Careful attention to cardiovascular monitoring and manipulation of hemodynamic variables is required and mechanical ventilation is needed in patients who progress to grade III/IV encepaholopathy. Renal replacement therapy is best achieved using a continuous hemodiafiltration system rather than hemodialysis in patients who present with acute liver failure. The development of cerebral edema is a common and frequently fatal complication, and requires meticulous care involving intracranial pressure monitoring. Patients are functionally immunosupressed and require frequent bacteriological surveillance, the incidence of both bacterial and fungal sepsis being very high. In some patients, such as those with lymphoma presenting as acute liver failure but requires stringent patient selection such that those patients with a good chance of spontaneous recovery do not undergo transplantation, while those with a poor prognosis can be considered.