A 65-year-old male with Caroli's disease had a fast rise in serum CA19-9 level during follow-up. Contrast-enhanced computed tomography (CT) revealed an irregular mass with a 3cm diameter, showing ring-like and delayed improvement in segment 8 of the liver. Gadolinium ethoxybenzyl diethylenetriamine penta-acetic acid-enhanced magnetic resonance imaging (MRI) demonstrated a mass with the hypointense signal on T1-weighted images, mildly hyperintense signal on T2-weighted images, and hypointense signal in the hepatobiliary phase. Positron emission tomography/CT revealed the absorption of (18) F-fluorodeoxyglucose in the hepatic mass and a nodule in the anterior mediastinum. The patient was diagnosed with intrahepatic cholangiocarcinoma and supraclavicular lymph node metastasis and had partial hepatectomy and lymph node dissection. Caroli's disease is an uncommon congenital condition with myriad small cystic dilatations of the peripheral intrahepatic bile duct as the primary lesion. The disease is not only often associated with recurrent cholangitis and hepatolithiasis but is also a high-risk group of intrahepatic cholangiocarcinoma. Caroli's disease requires regular screening for intrahepatic cholangiocarcinoma utilizing suitable imaging modalities, such as CT and MRI, as well as tumor marker testing.