Historically radiotherapy has always played a limited role for the treatment of HCC due to the low tolerance of the liver and the subsequent risk of radiation induced liver disease (RILD). Technologist advancements in radiation planning and treatment delivery such as Stereotactic Body Radiotherapy (SBRT) combined with Image Guided Radiotherapy (IGRT) has allowed us to further increase tumor dose while maximally sparing the surrounding not involved liver. Furthermore, together with the growing knowledge of radiobiological models in liver disease, several mono-institutional retrospective and prospective series are reporting very encouraging results. Therefore, radiotherapy might play a significant role for the treatment of unresectable HCC, alone or combined with other locoregional treatment such as transarterial chemoembolisation (TACE). The rationale for studying this technique is really strong and it should be tested in well designed prospective randomized clinical trials.