The present study deals with the natural history of 37 asymptomatic patients with cirrhosis and hepatocellular carcinoma, 25 with 2-9-cm tumors who were not surgically treated (first group) and 12 with tumors smaller than 4 cm who underwent resection (second group). All patients were in Child's A class. Two-year survival (according to life-table analysis by the Kaplan-Meier method) was 50% in the first group and 39% in the second group. This difference was not significant. In the first group no relation was found between survival and initial tumor size or alpha-fetoprotein levels. Ultrasound examinations at 3-mo intervals revealed the following patterns of tumor growth: (a) no significant growth during the follow-up (9 patients); (b) significant growth (tumor size at least doubling) only in the final stage of the disease (11 patients); (c) initial significant growth followed by a period of no increase in size (5 patients). These findings show that in our geographical area (a) 2-yr survival of untreated asymptomatic patients with hepatocellular carcinoma associated with cirrhosis does not differ from that of similar patients undergoing resection and (b) the tumor can exhibit long periods of no growth alternating with periods of exponential growth.