Metastatic tumors occur more frequently in the liver than in any other organ. Guided percutaneous fine-needle aspiration (FNA) of the liver is often recommended for confirmative diagnosis of the metastatic lesion, because of its simplicity, high yield, and reasonable safety. The authors studied retrospectively cytologic findings of 110 cases of metastatic tumors to the liver. The frequent primary sites were the stomach (23 cases), pancreas(19 cases), gallbladder(12 cases), and periampullary lesions(6 cases). Most of the metastases were carcinoma (106 cases). There were only 4 cases of sarcoma. The characteristic cytologic findings of FNA of meatastatic tumors were dirty background, abrupt change between hepatocytes and malignant cells, and desmoplasia. Some tumors displayed rather distinctive cytologic appearance that suggests primary sites. For example, the colonic adenocarcinoma showed tall columnar cells with a palisading arrangement, adenocarcinoma of gallbaldder showed focal squamous differentiation in some cases, and metastatic renal cell carcinoma and neuroblastoma showed also distinctive cytologic findings. Because the cytologic features of metastatic tumor are very similar to those of primary tumor, correct cytologic typing may be helpful in pursuit of an occult primary site of metastatic liver lesions, reducing extensive diagnostic investigation in poor prognostic patients.