Introduction: In Western countries, the most frequent aetiology of acute liver failure (ALF) is acetaminophen overdose, while in developing countries viral infections [hepatitis A virus and hepatitis B virus (HBV)] predominate. Aim: To evaluate the epidemiology, clinical characteristics, outcome and prognostic factors of survival of patients with ALF in Greece during the last 6 years. Results: A total of 40 patients, 28 females (70%), with a median age of 37.4+/-18.6 years (range: 15-84) with ALF were studied. HBV infection was the cause in 53% of them (compared with 74% from a previous study reported in the early 1980s), drug toxicity in 15% and undetermined in 13%. The overall survival was 57.5%, including 94% with and 15% without liver transplantation. Forty-five per cent of our patients had emergency liver transplantation in European Centers within a median time of 3.3 days (1-9) from admission. The total bilirubin level at admission and the development of infections were found to be significantly associated with poor outcome. Conclusions: Hepatitis B virus still remains the most important cause of ALF in Greece, but shows a significant decrease as compared with studies in the early 1980s. Almost half of our patients needed emergency liver transplantation and had a very good survival rate. The other 15% of the patients presented spontaneous survival only with intensive medical support.