The aim of this randomized controlled trial was to assess the efficacy of interferon alfa-2b (IFN) for the treatment of advanced hepatocellular carcinoma (HCC). Fifty-eight patients with HCC who were not suitable for resection, transplantation, ethanol injection, or arterial embolization were stratified according to their Okuda stage and randomized to receive IFN (3 ؋ 10 6 , 3 times a week, for 1 year) (n ؍ 30) or symptomatic treatment (n ؍ 28). Both groups were identical in terms of age, sex, performance status, presence of constitutional syndrome, Child-Pugh class, Okuda stage, multinodularity, portal thrombosis, and extrahepatic spread. Adhesion to IFN treatment was adequate in 27 patients, with a mean duration of treatment of 8 ؎ 3 months. However, IFN treatment was associated with side effects in 23 patients, leading to treatment discontinuation in 13 patients. Two of the 30 patients (6.6%) presented a partial response with greater than 50% size reduction and normalization of ␣-fetoprotein levels. The survival at 1 and 2 years according to intention to treat was not different between the 2 groups (58% and 38% vs. 36% and 12%, respectively, Breslow P ؍ .19, log rank P ؍ .14) and the absence of difference was maintained when dividing patients according to their Okuda stage. The probability of presenting tumor progression (P ؍ .17), or deterioration of Child-Pugh class (P ؍ .37), performance status (P ؍ .07), or Okuda stage (P ؍ .44) was not modified by IFN treatment. These results indicate that IFN is not properly tolerated in patients with cirrhosis and advanced HCC and that its administration prompts no benefit in terms of tumor progression rate and survival. (HEPATOLOGY 2000;31:54-58.