PURPOSE: To assess the CT findings of intrahepatic cholangiocarcinoma associated with hepatolithiasis. MATERIALS AND METHODS: The CT features of 26 patients with cholangiocarcinoma and hepatolithiasis were reviewed and compared with those of 23 patients with intrahepatic stones alone, acting as control subjects. CT findings were analyzed for tumor appearance and adjacency to hepatolithiasis. We studied clinical findings, noting the presence or absence of wall thickening or soft tissue attenuation within the bile duct, the luminal diameter of dilated bile duct, and the presence of periductal enhancement, and compared these with the findings for control groups. RESULTS: CT images of the tumor revealed a hepatic low-attenuating mass with peripheral rim enhancement(n=14, 54 %), or periductal thickening, or low-attenuating lesions in segmental dilatation of intrahepataic bile ducts(n=12, 46%). Most hepatic tumors were seen in areas adjacent to hepatolithiasis, or in a bile duct. Compared with control groups, patients with cholangiocarcinoma were old (p<0.001), and showed frequent weight loss and elevated CA 19 -9(p<0.001). With regard to the location of hepatolithiasis, luminal diameter, and periductal enhancement, no significant differences were seen between the two groups (p>0.05). CONCLUSION: When an intrahepatic low-attenuating mass, or peridutal thickening and low-attenuating lesions in segmental dilated intrahepatic duct are found associated in adjacent intrahepatic stones, intrahepatic cholangiocarcinoma should be considered.