CyberKnife, a new FSRT (Fractionated Stereotactic Radiotherapy) system which utilize a novel, light-weight, and high-energy radiation source, was introduced as a newly-developed therapeutic modality for solid tumors. In this report, we present 4 cases of hepatocellular carcinoma treated with CyberKnife. - 1. Single nodular hepatocellular carcinoma (stage II), 2. Advanced hepatocellular carcinoma with portal vein invasion (stage IVa), 3. Advanced hepatocellular carcinoma with metastatic intraabdominal lymphadenopathy (stage IVa), 4. Advanced hepatocellular carcinoma with right atrium invasion (stage IVb). Two patients showed complete response, and the other two patients showed partial response without major complications. After the treatment, they are in good general condition under observation at out-patient clinic. The present cases show that CyberKnife can give a chance of cure for small hepatocellular carcinoma and may also be used as an additional therapeutic modality for advanced hepatocellular carcinoma.