Fulminant hepatic failure accompanied by encephalopathy is a rare complication of acute liver disease, especially infection due to hepatitis A virus. We describe a 24-year-old woman and a 27-year-old man who developed this complication. One case presented with loss of consciousness and ended fatally. In the other the presenting symptoms were mental confusion and transient asterixis. Although hepatitis due to virus A is usually mild and the course favorable, one should be aware of the possibility of severe encephalopathy as a complication.