Fulminant hepatitis E has not been well characterized in industrialized countries. The aim of this study was to prospectively describe patients with acute hepatitis E presenting as fulminant hepatic failure, i.e. with encephalopathy and prothrombin index <50%. Between February 1997 and April 2005, seven patients with encephalopathy were diagnosed with acute hepatitis E using viral RNA detection. These patients were compared with 33 patients diagnosed with a mild form (absence of encephalopathy) of acute hepatitis E during the same time period. Patients were 65 +/- 11 years old. Five were active drinkers and six had chronic liver disease. All hepatitis E virus sequences evaluated (5/7) were of genotype 3. All patients but two died (71%). Four patients had no travel history. When compared with patients with a mild form of acute hepatitis E, active alcohol abuse and chronic liver disease were more frequent in patients with the severe form. Duration of hospitalization was longer. Aspartate transferase and bilirubin levels were significantly higher. Prothrombin index and accelerin levels were lower and death was more frequent. Acute nontravel-associated hepatitis E can appear as fulminant hepatitis with encephalopathy and coagulation disorders. Prognosis is severe and this may be due to the age at which it occurs and frequent underlying chronic liver disease.