The combination of biliary ascariasis and cholangiocarcinoma is rare. A 56-year-old female presented with progressive jaundice. Ultrasonography revealed a curvilinear structure with anechoic center consistent with ascariasis within the dilated common bile duct. Ultrasonography also demonstrated that a slightly echogenic soft tissue mass projecting into the mid segment of the common bile duct proved to be coexistent cholangiocarcinoma. Percutaneous transhepatic cholangiography did not confirm the presence of worm. In this report ultrasonographic and percutaneous transhepatic cholangiographic findings of the case are described and the relative merits of these two techniques are discussed.