Pathological changes and significance of intrahepatic peribiliary glands, hitherto poorly recognized intrahepatic elements, have been evaluated in our laboratory. In this report, we surveyed necroinflammatory and cystic changes of the peribiliary glands in 1,000 consecutive autopsy livers because these two changes coexisted frequently in the same liver. The necroinflammatory change was found in 228 livers (22.8%) and the cystic change in 202 livers (20.2%), and 103 cases showed both changes in the same liver. The necroinflammatory change was frequently found in intrahepatic cholangitis and extrahepatic biliary obstruction with bacterial infection, suggesting that biliary bacterial inflammation extends into these peribilary glands. This change was also frequent in systemic infection or septicemia without biliary bacterial infection, implying that the peribiliary glands were also damaged in such conditions without direct infection. The cystic change was frequent in livers with portal hypertension or obstruction, adult polycystic disease and necroinflammation of the glands, suggesting that the cystic change of the glands could occur as the result of the disturbance of intrahepatic circulation or as the result of inflammatory destruction of the glandular conduits. Some of peribiliary cysts may be of congenital origin. Dysfunction related to these pathological changes in the glands may diminish seromucous secretion and cause alterations in hepatic bile composition. The cystic change of the glands may retard bile flow by compressing bile duct lumina.