The degree of hepatocellular carcinoma vascularity in eight patients was assessed with Tc-99m MAA radionuclide angiography before and after treatment. For chemoembolization therapy, lipiodol and doxorubicin hydrochloride were administered intraarterially along with Gelfoam particles. The ratio of radioactivity in the hepatocellular carcinoma compared to that in the surrounding uninvolved tissue before therapy was 6.5-19.0 with a mean of 12.0. After therapy, the ratio dropped to 0.5-1.3. Because survival improved significantly after the therapeutic regimen used in these patients, radionuclide Tc-99m MAA angiography appears to be an accurate method for demonstrating successful embolization of the vascular supply in hepatocellular carcinoma.