We performed preoperative portal vein embolization (PVE) for 71 patients with hepatocellular carcinoma (HCC), 59 of whom underwent hepatectomy about two weeks after PVE. The purpose of the PVE was usually to embolize the portal vein supplying the area to be resected. After PVE, the non-embolized part of the liver became hypertrophic and the embolized part of the liver became atrophic. Of the 22 patients who underwent right lobectomy after PVE of the right first branch of the portal vein, the mean results of a test of 15-minute indocyanine green retention after PVE increased significantly less than the mean for six patients who could not undergo right lobectomy after PVE of their right first branch. The extent of this increase and the liver volume of the left lobe 4 weeks after right lobectomy were higher in another 15 patients who did not undergo PVE than 22 patients who underwent PVE. PVE is useful as one preparation for hepatectomy of patients with HCC, because the embolized part of the liver was damaged by PVE, but mean liver function was compensated by the part of the liver that was not embolized and regenerated.