Surgical resection is the best treatment for operable metastatic liver cancer. Large metastatic cancer usually has low operability, so a debulking modality of mass is needed to increase operability. Chemotherapy and radiotherapy were commonly used as neoadjuvant treatments. Cyberknife stereotactic radiosurgery systems were only considered as one of the palliative treatment modalities for inoperable or surgically complex tumors. But, in this case, we applied Cyberknife as the preoperative debulking modality for large hepatic metastasis of adrenocortical carcinoma. After Cyberknife treatment 3 cycle×2,700 cGY, tumor size decreased (metastatic liver mass decreased to 15×9 cm from 19×12.5 cm, adrenal mass decreased to 5×3 cm from 7.4×4.5 cm). We could then resect the tumor completely by extended right hemihepatectomy & right adrenalectomy. A preoperative multidisciplinary approach, including chemotherapy and radiation therapy can be considered to increase operability. So, cyberknife can be considered an additional modality as a neoadjuvant radiotherapy.