BACKGROUND/AIMS: Biliary cystadenomas and cystadenocarcinomas are rare intrahepatic cystic neo plasms that are pathologically characterized by multilocular appearances. We analyzed the clinical pathologic and radiologic features of these rare diseases. METHODS: Nine patients with intrahepatic biliary cystadenoma (n=6) or cystadenocarcinoma (n=3) which was surgically proven were included in this retrospective study. RESULTS: There were 8 women and one man, with the mean age of 41 years (range, 23-60 years). Abdominal pain and/or distension were the major clinical symptoms. The appearance of the tumors was either unilocular cystic or multilocular cystic. The tumors did no communicate with bile ducts. Papillary excrescences, nodular thickening of internal septa and mura nodules were seen in one case of cystadenoma and in all three cases of cystadenocarcinomas. Patho logically, these tumors were typically well-encapsulated and composed of multiple cysts that were lined with biliary type epithelium. After complete resection, all patients except one who had positive lymph nodes did not experience recurrence of tumor. CONCLUSIONS: When a well-encapsulated, mul tilocular intrahepatic cystic mass is detected, especially in a middle-aged woman, biliary cystadenoma and cystadenocarcinoma should be suspected and resected.