Cholangiocarcinomas frequently develop in patients with underlying diseases of the bile ducts, including liver fluke infection, biliary stones, primary sclerosing cholangitis, recurrent pyogenic cholangitis (oriental cholangiohepatitis), benign biliary tumors, exposure to thallium oxide, choledochoenteric anastomosis, choledochal cyst, and ductal plate malformations (i.e., biliary hamartoma, polycystic disease, and congenital hepatic fibrosis) [1–5]. Of these, evidence indicating that Clonorchis sinensis and biliary stones are etiologic factors of cholangiocarcinoma is reviewed, and the radiologic findings of clonorchiasis, stones, and cholangiocarcinomas are presented. In the Far East and Southeast Asia, liver fluke infections due to C. sinensis or Opisthorchis viverrini are believed to be the most important causes of cholangiocarcinomas [6, 7]. Clonorchis sinensis infects about 7 million people in East Asia, including China, east Russia, Korea, and Vietnam [8]. Multiple epidemiologic, histopathologic, and experimental studies have suggested a close relation between C. sinensis infection (clonorchiasis) and the tendency for malignant transformation of the biliary epithelium in humans and experimentally infected animals [7–9]. Chronic infection or bile stasis in the biliary tree is considered an essential factor in cholangiocarcinogenesis. Some studies [1, 10] have hypothesized that the epithelium of the bile duct, if persistently exposed to biochemically altered bile, may undergo the sequence of mucosal adenomatous hyperplasia to metaplasia to dysplasia to carcinoma. Hepatolithiasis, or intrahepatic duct stones, is also common in East Asia [11]. In this endemic area, several studies in the literature on the frequency of a cholangiocarcinoma related to intrahepatic duct stones have reported ranges of 1.7% to 12.5% [10, 12–20]. In patients with intrahepatic duct stones (mostly brown pigment stones), the bile usually is infected with Escherichia coli [21]. Long-lasting bile stasis and bacterial infection are considered significant causative factors of a cholangiocarcinoma [22, 23]. The formation of stones has been closely associated with clonorchiasis, as C. sinensis worms, eggs, and bile with high mucin contents serve as nidi [2, 24–27]. Bile stasis, secondary bacterial infection, and injury of the bile duct epithelium also may facilitate stone formation [26, 27]. There is evidence for the close link between clonorchiasis, recurrent pyogenic cholangitis, calcium bilirubinate stones, and cholangiocarcinomas [1, 11, 27].