A clinical trial of transarterial chemoembolization for hepatocellular carcinoma using pirarubicin (4'-0-tetrahydropyranyladriamycin, THP) was performed. Although adriamycin has been widely utilized for chemoembolization on the hepatocellular carcinoma, myocardial toxicity has been occasionally observed as its serious side effect. THP has an advantage that myocardial and gastrointestinal complications are less frequent than adriamycin. Ten patients with hepatocellular carcinoma were included in this study. Emulsion of 30-60 mg of THP and lipiodol was administered through a catheter inserted into the right or left hepatic artery, and thereafter, transarterial embolization was performed. PR was observed in seven of the ten patients and MR in two. Only one patient showed NC. Serum alpha-fetoprotein levels decreased in nine of the ten patients, and PIVKA II in the peripheral blood disappeared in all five patients that had been positive before the chemo-embolization four weeks after the treatment. Side effects included nausea in two patients just after administration of THP, but leukopenia below 2,000/cmm, was not observed in any of the patients. No other serious side effect was observed. From these results, THP was suggested to be a useful chemotherapeutic agent for hepatocellular carcinoma.