Until February 1984, 75 patients have undergone radiotherapy using the following two methods: 1. During surgery, electron 3000 rads were given. 2. For external irradiation, X-ray or fast neutron was given with a TDF (time dose and fractionation factor) of 80-110. Hepatocellular carcinoma: There were 14 patients including 6 preoperative irradiation and 8 unresectable cases. Improvements were obtained image diagnostically in 9 of 13 patients. Serum AFP level decreased in 6 of 8 patients. And the resected specimens revealed degeneration or necrosis of the cancer tissue. Radiotherapy can given beneficial effect to the patients with tumor emboli within the portal vein, or even disappearance of the tumor emboli sometimes could be seen. Bile duct carcinoma: There were 30 patients including 12 with intraoperative irradiation. 2 irradiated during surgery and external irradiation, and 16 with external irradiation. More than 1-year survivals observed in 6 of 18 unresectable cases. The longest survival of non-curative operation was 6.5 years with treatment. Pancreas carcinoma: There were 31 patients including 29 unresectable and 2 resectable cases. Prolongation of survival time in unresectable patients was not obtained with an interval of 5 months at 50% survival rate. But some clinical complaints were relieved. We concluded that radiotherapy is useful to improve surgical curability by decreasing the cancer cell viability, to give a wider surgical indication if portal tumor emboli can be eliminated, to prevent early tumor recurrence, and to give some beneficial effects to unresectable or recurrent patients.