Segmental arterioportal chemoembolization via hepatic artery with overflow to the segmental portal vein was performed in 41 patients with hepatocellular carcinoma. Emulsion of doxorubicin (mean 37 mg) and two-to-three volume of iodized oil (mean 11 ml) was infused from a segmental artery of the liver until the segmental portal branches around the tumor were visualized fluoroscopically. By the iodized oil accumulation, the tumors were divided into five types: single nodular (SN); single nodular with proliferation (SN-P); multinodular fused (MN-F); multinodular (MN); and massive. Massive and MN types showed high incidence of local recurrence. However, SN-P and MN-F types showed a good tumor response and no local recurrence. In 32 unresected cases the overall response rate was 53%, the 1-year actuarial survival was 90% and 3-year survival was 43%. Six of nine operative specimens revealed complete necrosis of the tumor microscopically and three showed 90–95% necrosis. Thick fibrous capsules were found in all nine resected cases around the necrosis both of the tumor and of the non-cancerous parenchyma. This therapy was regarded as having a great capacity to kill the infiltrative portion of localized tumor and the thick capsule may be a peculiarity of this therapy which played a major role in guarding against regrowth of the tumor.