Yttrium-90 radioembolization has emerged as a novel therapy for hepatocellular carcinoma (HCC) of intermediate or advanced stage. Yttrium-90 has characteristics of short half-life and tissue penetration depth. Potent anti-cancer effect by this isotope enables to kill the tumor for 6 months after administration. Although transarterial chemoembolization (TACE) is the standard modality for multinodular HCC without vascular invasion, big size or numerous nod-ules does not allow enough treatment effect of TACE. Post-embolization syndrome resulting poor quality of life, liver dysfunction and hepatic arterial damage are other pitfalls of TACE. In several studies, radioembolization showed survival comparable to TACE, shorter hospital stay and less treatment sessions. In advanced HCC with portal vein invasion, radioemboliza-tion demonstrated similar or better survival compared with sorafenib. The atrophy of lobe treated by radioembolization and hypertrophy in the contralateral lobe can be called radia-tion lobectomy, which makes it possible to perform a following curative therapy. The role of radioembolization in unresectable HCC in terms of downstaging or bridge to transplantation needs to be further studied. Radioembolization is contraindicated in HCC patients with main portal vein occlusion and with poor liver function. The International guidelines for HCC have some limitations and thus rooms for radioembolization to be incorporated.