In a multicentered randomized prospective study, hepatic arterial embolization using gelatin sponge (GS) alone or together with anticancer agents was performed in a total of 112 patients with hepatocellular carcinoma to ascertain the clinical availability of the anticancer agents combined with gelatin sponge. Envelopes, each of which contained a note mentioning one of the following three kinds of regimens, were allocated at random to the participating institutes: 1) GS + mitomycin C (MMC) 10 mg + adriamycin (ADR) 20 mg (group A, n = 45), 2) GS + MMC 10 mg + ADR 20 mg + 200 mg/day of oral 5-fluorouracil (5-FU) (group B, n = 36), and 3) GS + 200 mg/day of 5-FU (group C, n = 31). The envelopes so allocated were opened just prior to embolization, and the treatment was carried out as instructed. Survival rates were estimated according to the method of Kaplan-Meier for comparative analysis. The survival rate was significantly higher in group A than in group C on days 465 (p less than 0.05). It was also significantly higher in group B than in group C on days 279, 558 and 651 (p less than 0.05) as well as on days 372 and 465 (p less than 0.01). These observations suggest that this embolization using anticancer agents such as MMC and ADR, compared with the embolization using gelatin sponge alone, may exert a life-prolonging effect in patients with hepatocellular carcinoma.