A prospective study of acute symptomatic viral hepatitis in childhood was started at the Department of Infectious Diseases of Padua (Italy) in 1978. During an 8-year period, 93 consecutive patients (aged 3 months to 12 years) fulfilled the diagnostic criteria, including five (5.5%) cases classified as non-A, non-B hepatitis. This figure is lower than that generally reported in adult patients, probably because of a lower exposure of children to blood and contaminated materials. Two of the five children with non-A, non-B hepatitis had received blood transfusions, while three had no history of parenteral exposure. Although the outcome of the illness was favorable in all five patients, a variety of clinical features could be observed: two children had a mild, short-lasting disease, anicteric in one case, while three had a polyphasic pattern of transaminases with delayed biochemical resolution, including one patient with deep jaundice and severe early phase features. These findings suggest that in children, as well as in adults, non-A, non-B hepatitis is probably a heterogeneous entity induced by different agents with different modes of transmission.