Lymphoplasmacyte-rich meningioma (LPM) is one of the rarest variants of meningioma and those LPMs that arise in the intraventricular space are even rarer. LPMs are classified as grade I (benign) tumors with a low proliferative rate and diagnosis is made through the histological identification of high numbers of inflammatory cells (lymphocytes and plasma cells) in the resected tumor tissue. In the current case, magnetic resonance imaging of a 37-year-old woman who presented at our neurosurgery department following a generalized tonic-clonic seizure revealed a partially mortified intraventricular mass, which had caused pronounced peritumoral edema and had a relatively rough surface. Surgical resection was performed. Histological analysis revealed large numbers of inflammatory cells, confirming the diagnosis of LPM, but also indicated that the lesion was positive for the proliferation marker Ki-67. Follow-up magnetic resonance imaging 3 months after surgery revealed no residual tumor or recurrence.