It is well known that cytomegalovirus infection is often accompanied by hepatitis, but there have been few comparative studies with respect to clinical features of cytomegalovirus-associated hepatitis and other acute viral hepatitides. In the present study, clinical and pathological features of 11 acute sporadic cytomegalovirus hepatitis infections in previously healthy adults were compared with those of 45 acute sporadic viral hepatitis, including type A, type B and type C. As a result, the characteristics of cytomegalovirus hepatitis were a long-lasting fever, splenomegaly, atypical lymphocytosis, a mild transaminasemia, a low ratio of alanine aminotransferase level to lactate dehydrogenase level, and mild hepatic histopathological changes.