Since 1983 we have performed transcatheter oily chemoembolization (TOCE) using adriamycin (40-100 mg), Lipiodol (5-20 ml) and Gelfoam in the treatment of 100 cases with unresectable hepatocellular carcinoma. Adriamycin was dissolved in a fluid equal in specific gravity to Lipiodol and the adriamycin solution was mixed with 3 volumes of Lipiodol, making an adriamycin-in-oil emulsion (AOE). After TOCE, the blood concentration of adriamycin was obviously lower than that after one-shot injection because of the slow release of adriamycin from the AOE. Also, in cases of hepatic resection after TOCE, there was a clear difference in the adriamycin concentration between the tumor and the normal hepatic tissue. The cumulative survival rates for the 100 patients treated by TOCE were: 6 months 81.9%, 1 year 53.8% and 2 years 36.5%. Thus, improvement was found in comparison with the cumulative survival rates for 104 patients who underwent hepatic embolization without Lipiodol, which were 6 months 67.4%, 1 year 45.2% and 2 years 16.3%. AOE retained in the tumor as microemboli brings about the slow-releasing effect of adriamycin. Furthermore, by adding the effect of Gelfoam embolization, TOCE has a strong antitumor effect.