Autoimmune hepatitis is a chronic necroinflammatory liver disorder of unknown cause associated with circulating autoantibodies and hypergammaglobulinemia. We report two pediatric cases of type 1 autoimmune hepatitis with normal serum immunoglobulin G levels who presented with fulminant hepatitis. The cases were associated with hereditary spherocytosis or atrioventricular septal defect. The first case was a 13-year-old boy with hereditary spherocytosis and gallstones. Acute cholecystitis and cholangitis developed during his clinical course and cholecystectomy, splenectomy and liver wedge biopsy were performed. The second case was an 8-year-old girl with repaired atrioventricular septal defect. In both cases, antinuclear antibody tests were positive and immunoglobulin G levels were normal. Interface hepatitis with moderate lobular inflammation were noted on their liver histology. They responded to the treatment of prednisolone and ursodeoxycholic acid.