In order to obtain less severe toxic reactions and maximal therapeutic effects, 729 patients with cancer of the liver or biliary tract or pancreas were treated with intra-arterial infusion of 5-FU and mitomycin C (MMC) alone or in combination with 2450 MHz microwave hyperthermia. Approximately 60% of the patients with primary hepatic cancer showed objective response to the intra-arterial infusion of 5-FU and MMC. However, many patients developed hemorrhage of esophageal varices, gastroduodenal ulcers, jaundice and ascites because of high incidence of hepatic cirrhosis with hepatoma. Fifty percent survival period was only 5.2 months and 26% of the patients so treated survived a year or longer. Metastatic liver cancers, on the contrary, showed better results as compared to those of the primary liver cancer. Fifty percent survival period for metastatic liver cancer was 8.0 month and 42 percent of the patients survived a year or longer. For the cancer of head of the pancreas, the combination of intra-arterial infusion chemotherapy and microwave local hyperthermia was proved to be the most effective way to control cancer. Nine patients before 1975 were treated with intra-arterial infusion chemotherapy alone and 25 patients in and after 1975 were treated by intra-arterial infusion chemotherapy in combination with hyperthermia.(ABSTRACT TRUNCATED AT 250 WORDS)