The authors used microcholangiography to demonstrate the feasibility of the technique and the features of the normal and the obstructed biliary systems. Furthermore, they attempted to explain the pathophysiology of cholangiography-related septicemia with this technique. Extrahepatic bile ducts (EHBD) of 40 rabbits were ligated, and microcholangiography was carried out with infusion of barium suspension immediately as well as one, three, and five days after ligation. Microradiographic technique was used and the findings were correlated with histopathologic features. The intrahepatic microbiliary system such as interlobular bile ducts and ductules were well visualized. After EHBD ligation, ductules were tortuously dilated. The histologically observed ductular proliferation in many hepatobiliary diseases could be attributed in part to the tortuosity of bile ductules, particularly when biliary obstruction is present. Regurgitation of barium into hepatic sinusoids was demonstrated in 36 rabbits (90%) and probably was caused by rupture of interlobular bile ducts and ductules.