Autoimmune hepatitis is an inflammatory disease of the liver of unknown etiology that progresses toward cirrhosis and liver failure and is generally responsive to immunosuppressive treatment. The presence of anti-smooth muscle antibodies with anti-actin specificity and of anti-liver kidney microsomal antibodies defines two distinct subgroups of the disease. An autoantibody against liver cytosolic antigens has recently been described. Management of autoimmune hepatitis relies on immunosuppressive therapy with steroids alone or combined with azathioprine. When the disease is poorly controlled, despite good patient compliance to therapy, cyclosporin should be recommended. Progressive liver disease in chronic hepatitis B in adults has been associated with the presence of precore mutants of hepatitis B virus. In children, the presence of precore mutants seems not to affect the rate of seroconversion to anti-hepatitis B e antigen. However, high viremic levels of precore mutants are associated with persistent viral replication and liver disease. Interferon alfa seems to be less effective in children than in adults in the treatment of chronic hepatitis B; however, it hastens the seroconversion rate to anti-hepatitis B e antigen, accelerating the spontaneous clearance of the virus in children with already low levels of viral replication. Blood transfusions, especially those received in the perinatal period, are the single most important source of infection with hepatitis C in childhood. HIV coinfection is a major risk factor for vertical transmission of hepatitis C virus in pregnant women. Chronic hepatitis C in children is usually an asymptomatic disease associated with mild to moderate fluctuation of aminotransferase activities and histologic features of mildly active hepatitis. Severe active hepatitis and cirrhosis are infrequent during childhood and adolescence. Interferon may have a place in the treatment of chronic hepatitis C in children.