A method to prepare cisplatin suspended in an oily lymphographic agent, Lipiodol (LPS), has been established to deliver cisplatin to hepatocellular carcinoma (HCC) by the hepatic artery. Seventy-one patients, one Stage I, 16 Stage II, 16 Stage III, and 38 Stage IV, were treated with LPS therapy. A partial response was obtained in 33 cases (46.5%), a minor response in 20 cases (28.2%), and no change in 18 cases (25.3%). In 34 patients whose serum alpha-fetoprotein (AFP) levels were greater than 400 ng/ml, the serum AFP levels decreased in 31 patients (91.2%). The AFP decreased by more than 50% in 25 cases (73.5%) and more than 75% in 19 cases (55.9%). The plasma des-gamma-carboxy prothrombin (DCP) levels decreased in all of the 26 DCP-positive patients. The survival rate was 77% at 6 months and the 1-year survival rate was estimated to be 55%. The patients treated with LPS therapy survived longer compared with patients given Lipiodol containing neocarzinostatin by the hepatic artery. Complications such as acute gastroduodenal mucosal lesions (24%), cholecystitis (2.8%), pancreatitis (7%), delayed jaundice (7%), and hepatic encephalopathy (4.2%) were observed after therapy. The peak plasma platinum (Pt) concentrations determined as ultrafilterable Pt occurred 5 to 20 minutes, and 5 to 60 minutes as total Pt after the end of LPS injection. The Pt concentrations in the tumor tissues were 42 times higher in four operated cases and 7.1 times higher in six autopsy cases than those in the nontumorous tissue. These results suggest that LPS selectively accumulates in the HCC, is long-lasting and gradually releases the drug. In addition it is effective as a new anti-cancer therapy for hepatocellular carcinoma.