PURPOSE: To evaluate the role of bile duct obstuction in the development of atrophy of the liver, using ananimal model. MATERIALS AND METHODS: Seven rabbits were divided into two groups : group 1(n=5), in which therewas selective bile duct ligation, and group 2(n=2), which underwent a sham operation. Each group was evaluated using CT for changes in hepatic volume after selective bile duct ligation or a sham operation. In group I, the diameter of dilated bile duct was measured 2, 4, 8, 12 and 16 weeks after bile duct ligation, while gross andhistologic change were evaluated in all cases. RESULTS: In group 1, bile duct dilatation was seen on CT two weeks after selective bile duct ligation, and did not change significantly during follow-up. In four of five cases, CT revealed no evidence of significant atrophy of the involved segment. Pathologic specimens, however, revealed dilatation of the bile duct, periductal fibrosis, infiltration of chronic inflammatory cells, and periportalfibrosis. One of five cases showed segmental liver atrophy after selective bile duct ligation. In addion to the above pathologic findings, there was obstruction of the portal vein by foreign body reaction. In group 2, no evidence of dilated bile duct or liver atrophy was revealed by CT or pathologic specimen after a sham operation. CONCLUSION: During long-term follow-up of 16 weeks, obstruction of the bile duct did not play a major role in the development of lobar atrophy in the rabbit.