One hundred and sixty-eight patients with unresectable primary liver cancer were prospectively studied by members of the Eastern Cooperative Oncology Group. These patients were randomized to receive treatment with oral 5-Fluorouracil (5FU), oral 5-Fu plus Streptozotocin, oral 5-Fu plus Methyl-CCNU or Adriamycin. The single agent treatments (oral 5-Fu and Adriamycin) were associated with less gastrointestinal toxicity than were the oral 5-Fu treatment combinations. A total of 15 partial responses were reported. Adriamycin appears to be the most active agent and responsible for 9 of the 15 responses. No response was seen in any of the 48 patients randomized to oral 5-Fu alone. The survival associated with oral 5-Fu alone was significantly shorter than the survival time associated with the remaining 3 treatment programs among both North American and South African patients. A multivariate model of survival was formulated. Covariates of prognostic significance were treatment, initial performance status and sex. South African black patients had a shorter survival time than North American black patients. Excluding oral 5-Fu from consideration, prognostic variables appeared to dominate any differences between the remaining treatments under study.