A 15-year-old boy was referred to our hospital with a rare case of inflammatory pseudotumor (IP) in the lateral ventricle manifesting as complaints of headache and low-grade fever. Computed tomography and magnetic resonance imaging demonstrated a well-demarcated and enhanced tumorous lesion in the right lateral ventricle. Intraoperative findings showed a hard mass with feeding arteries from the choroid plexus around the foramen of Monro in the right lateral ventricle, although the mass was not attached to the wall of the lateral ventricle. The lesion was totally resected, and the histopathological diagnosis was IP. The present and previous cases suggest that good outcomes are obtained by surgical removal and treatment of hydrocephalus. IP should be considered in the differential diagnosis of hard tumorous lesions with good enhancement and no tumorous staining in the ventricle.