Syncytial giant-cell hepatitis was recently reported to be related to a paramyxovirus and carried a poor prognosis. Twelve patients with syncytial giant-cell hepatitis seen in an 8 1/2-year period in our institute were reviewed. Seven patients had an identifiable aetiological cause: two had autoimmune chronic active hepatitis, one had primary sclerosing cholangitis and autoimmune chronic active hepatitis, two presented with prolonged jaundice after acute hepatitis A and B, one had chronic Epstein-Barr virus infection and the remaining patient was seropositive for antibody to hepatitis C virus. One patient with autoimmune chronic active hepatitis who had frequent syncytial giant cells in the liver responded promptly to corticosteroid treatment and a repeated biopsy 3 years later showed histological improvement with a marked decrease in the number of syncytial giant cells. Of the remaining five patients, three ran a clinical course of fulminant hepatic failure and two had severe chronic active hepatitis. These data indicate that syncytial giant-cell hepatitis is unlikely to be related to only one single aetiological agent and that syncytial giant-cell hepatitis does not always carry an ominous prognosis.