Although the causes of fulminant hepatic failure (FHF) remain cryptogenic in many cases, a few reports have reviewed the pathological findings of native livers to evaluate the etiology. We report 2 cases of infantile cryptogenic FHF with unique vascular obstructive changes in the native livers. Clinically, it was notable that these 2 patients developed FHF very early in life, at 2 months and 5 months of age, respectively. One patient died from chronic rejection associated with hepatic veno-occlusive disease 4 months after transplantation. Histologically, hepatocytes in the native livers were completely destroyed in both patients, and vascular findings revealed obstruction of central veins in 1 patient and obstruction of portal veins in the other patient. Although the pathogenesis of vascular obstructions is not yet understood, this study suggests that an obstructive vascular event may be a contributing etiologic factor of FHF in infancy.