Background: Single-agent doxorubicin has been widely used to treat unresectable hepatocellular carcinoma (HCC), but the response rate is low (<20%) and there is no convincing evidence for improved survival. Cisplatin, interferon, doxorubicin, and fluorouracil (PIAF) used in combination, by contrast, has shown promise in a phase II study. We compared doxorubicin to PIAF in patients with unresectable HCC in a phase III trial. Methods: Patients with histologically confirmed unresectable HCC were randomly assigned to receive either doxorubicin or PIAF every 3 weeks, for up to six cycles. The primary endpoint was overall survival, and secondary endpoints were response rate and toxicity. Survival differences were calculated using the Kaplan-Meier method. Treatment groups were compared for differences in the incidence of adverse events using chi-square tests. All statistical tests were two-sided. Results: The median survival of the doxorubicin and PIAF groups was 6.83 months (95% confidence [CI] = 4.80 to 9.56) and 8.67 months (95% CI = 6.36 to 12.00), respectively ( P = 0.83). The hazard ratio for death from any cause in the PIAF compared with the doxorubicin groups was 0.97 (95% CI = 0.71 to 1.32). Eighty-six of the 94 patients receiving doxorubicin and 91 of the 94 receiving PIAF were assessable for response. The overall response rates in the doxorubicin and PIAF groups were 10.5% (95% CI = 3.9% to 16.9%) and 20.9% (95% CI = 12.5% to 29.2%), respectively. Neutropenia, thrombocytopenia, and hypokalemia were statistically significantly more common in patients treated with PIAF than in patients treated with doxorubicin. Conclusion: Although patients on PIAF had a higher overall response rate and better survival than patients on doxorubicin, the differences were not statistically significant. PIAF was also associated with increased treatment-related toxicity. The prognosis of patients with unresectable HCC remains poor.