In the period 1985-1988, 62 focal liver lesions in 58 cirrhotic patients were studied by ultrasonography; 12 of these focal lesions were documented to be regenerating lesions by echo-guided fine-needle biopsy. During an average follow-up period of 10.2 months (range 3-22 months), hepatocellular carcinoma was subsequently found in 10 of the cases of regenerating nodules, whereas the initial diagnosis of regenerating nodule was confirmed in the remaining two cases. Based upon this finding, it is suggested that every focal mass visualized by ultrasonography in a cirrhotic liver should either be considered to be a neoplastic lesion or at least a preneoplastic lesion if the possibility of either a metastatic or benign lesion (eg, hemangiomas, focal fatty liver change areas) can be excluded. Therefore either fine-needle aspiration or biopsy of all ultrasonographically revealed mass lesions within a cirrhotic liver is advised, such that early appropriate treatment for hepatocellular carcinoma can be instituted.