PURPOSE: We evaluated the frequency of detection of small hepatic cystic lesion(SHC) on abdominal CT films and its significance in patients with extrahepatic malignancies. METHODS AND MATERIALS: We retrospectively reviewed the abdominal CT films of a total 1112 patients to determine the frequency of detection of SHC, and 62 patients who had both extrahepatic malignancies and SHC were selected. A total 106 SHC determined as benign or malignant in 40 patients was analyzed according to the size(< 1 cm, 1 2cm), the number(1, 2 4, >4), the margin(well-defined, iil-defined),and the location(central, peripheral) of individual cystic lesions. The findings of follow-up CT and ultrasonography and the results of biopsy were also reviewed. The frequency of combined renal cyst was also considered. RESULT: SHC of those 62 patients were classified as benign(27 patients, 43.6%), malignant(13 patients, 20. 9%), or undetermined(22 patients, 35.5%) by the follow-up CT, ultrasonography, and biopsy. Most benign SHC (74.4%) measured under 1 cm, but 75% of the malignant SHC were in 1 -2cm in size. The percentage of the malignancy in one and two to four SHC was 37.5% and 40%, respectively. The margin of SHC was ill-defined in 67.9% of the benign and 64.3% of the malignant lesions. SHCs were mainly located at the periphery of the liver(benign :62.7%, malignant: 64.3%). Coexisting renal cyst was rare. CONCLUSION: SHC is not uncommon finding(13.2%) in patients with extrahepatic malignancy and has a high probablity of metastasis when it is larger than 1 cm, which should be closely followed and intensively studied further.