Surgery and radiotherapy are mainly used for plasma cell neoplasm which constitutes about 1~2% of human malignancy. The authors carried out Fractionated Stereotactic Radiotherapy(FSRT) on the residual tumor after the subtotal removal of intracranial plasmacytoma. A huge mass lesion was observed on MRI (magnetic resonance image) in the left anterior and middle cranial fossa of a 63-year-old man with left exophthalmus which lasted for a month, and was suspected as a meningioma with strong contrast enhancement. Extramedullary plasmacytoma was diagnosed on histopathological examination. After the surgery, FSRT was also carried out on the residual tumor which invaded the skull base. One-year follow up after FSRT showed contrast enhancement only in the left sphenoid bone on MRI, which indicated significant decrease in the size of the tumor without any abnormal neurologic deficits. We treated intracranial plasmacytoma which invaded left anterior and middle cranial fossa and surrounded cavernous sinus without cranial nerve deficit through subtotal tumor removal and FSRT.