A 67-year-old right-handed woman presented with a case of hemangiopericytoma in the lateral ventricle manifesting as digit number memory disturbance, sensory aphasia, and right quadrantanopsia. Magnetic resonance imaging demonstrated a 6-cm homogeneously enhanced mass in the trigone of the left lateral ventricle. The tumor was totally removed via the left inferior temporal gyrus. The histological findings were consistent with hemangiopericytoma. Differential diagnosis of hemangiopericytoma from meningioma and solitary fibrous tumors is very important because the clinical behavior of hemangiopericytoma is very aggressive, including local recurrence or distant metastases in the central nervous system and periphery. Histological confirmation is required to make a definitive diagnosis. The present patient did not receive radiation therapy, but developed no local recurrence or metastases. Complete surgical resection and awareness of hemangiopericytoma in the lateral ventricle are very important for good clinical outcome.