Peribiliary capillary plexus (PCP) is a network of capillaries which arise from the hepatic artery surrounding the intrahepatic bile ducts. We immunohistochemically investigated the density of PCP around interlobular bile ducts in various chronic liver diseases including primary biliary cirrhosis (PBC) (n = 47), autoimmune hepatitis (AIH) (n = 12), chronic hepatitis B (n = 16), chronic hepatitis C (n = 19), liver cirrhosis due to hepatitis B virus (n = 13), liver cirrhosis due to hepatitis C virus (n = 20), alcoholic hepatitis (n = 20), alcoholic liver cirrhosis (n = 17), using human liver biopsies fixed in formalin and embedded in paraffin wax. PCP was immunohistochemically detected by an endothelial marker, the CD34 antigen. The number of PCP per duct was 1.21 ± 0.18 in normal livers. Compared with normal liver, vasopenia was observed in PBC and AIH, the number in which was 0.93 ± 0.34 (P< 0.0001) and 0.82 ± 0.38 (P< 0.005) per duct, respectively. In contrast, increased number of PCP was observed in liver cirrhosis due to hepatitis B or C virus, alcoholic hepatitis, and alcoholic liver cirrhosis, the number in which were 1.59 ± 0.37 (P< 0.005), 1.55 ± 0.52 (P< 0.02), 1.38 ± 0.23 (P< 0.02) and 1.61 ± 0.33 (P< 0.002) per duct, respectively. These data suggest that PCP may be destroyed in autoimmune liver diseases, including PBC and AIH, but PCP may proliferate in other inflammatory and alcoholic liver diseases.