We have recently noted a hitherto undescribed hepatic hemosiderosis confined to endothelial cells of the portal tract in chronic viral hepatitis. In this study, this lesion was surveyed in 156 liver biopsy specimens from patients with chronic hepatitis C and in 21 liver biopsy specimens from patients with chronic hepatitis B. As controls, we examined 110 liver biopsy specimens from patients with primary biliary cirrhosis (PBC), 36 from patients with alcoholic liver injury, nine from patients with autoimmune hepatitis (AIH), and five from patients with primary hemochromatosis. Hemosiderin deposition was found in the endothelial cells of venous vessels in portal tracts regardless of the presence or degree of hemosiderin deposition in hepatic parenchyma. This phenomenon was observed in 65 of 156 cases (42%) of chronic hepatitis C and in eight of 21 (38%) cases of chronic hepatitis B. In controls, this lesion was frequent in AIH (78%), but infrequent in PBC (8.1%) and alcoholic liver injury (11%). The incidence of this lesion showed significant differences between chronic hepatitis C, B, and AIH, and between PBC and alcoholic liver injury. There was a positive correlation between the progression of disease and the incidence of this feature in chronic viral hepatitis; the incidence was 18.3% and 11.1% in milder chronic hepatitis C and B, respectively, and 61.2% and 58.3%, respectively, in more severe cases. However, this correlation was not evident in either PBC or alcoholic liver injury. This hemosiderin deposition was positively correlated with the degree of piecemeal necrosis in chronic hepatitis C, and to a lesser degree, the positive correlation was shown in chronic hepatitis B. These findings suggest that the progression of chronic hepatitis and the piecemeal necrosis in chronic hepatitis C and B, followed by the release of hepatocellular iron to portal and periportal areas, are directly or indirectly responsible for endothelial hemosiderosis. Further studies focusing on this peculiar phenomenon in relation to choice of therapy and evaluation of chronicity of viral hepatitis are encouraged.