The factors that contribute to the effect of portal vein embolization before hepatectomy for hepatocellular carcinoma are unclear. Sixty-six patients with hepatocellular carcinoma were enrolled in the study. Changes in liver function, portal vein pressure, and liver volume after embolization were examined. A multiple linear regression analysis was performed to identify factors that independently contributed to the effects of portal vein embolization. The acceptable volume ratio of the remnant liver was calculated from liver function and compared with the volume ratio of the non-embolized liver. No postoperative deaths were observed after portal vein embolization or hepatectomy. Serum total bilirubin and prothrombin time did not change significantly after portal vein embolization. In patients who underwent arterial embolization before portal vein embolization, aminotransferase levels increased significantly. The only factor that could significantly predict the atrophy effects of portal vein embolization was previous arterial embolization. The volume ratio of the non-embolized liver was smaller than the acceptable volume ratio of the remnant liver in 18 of 40 patients and increased over the acceptable volume ratio in all cases after portal vein embolization. Portal vein embolization induced atrophy or hypertrophy of the embolized or non-embolized liver sufficiently, even when the liver was dysfunctional or cirrhotic. The atrophy effects were significant, especially when arterial embolization had been performed before portal vein embolization.