We describe a rare case of a pediatric patient with active GB virus C (GBV-C)/hepatitis G virus (HGV) infection who died of fulminant hepatic failure within less than a month after the onset of jaundice. The child tested negative for all other known hepatitis viruses and had no history of blood transfusions. This observation suggests that although GBV-C/HGV is usually not pathogenic to the liver, it may be associated with certain idiopathic forms of fulminant hepatitis. Whether this association is etiological or circumstantial remains to be seen.