This report concerns a 64-year-old woman with a lymphoplasmacyte-rich meningioma. Radiographically and macroscopically, the tumor had the appearance of an ordinary meningioma. Components of the meningothelial cells were positively immunostained for epithelial membrane antigen. The results of immunohistochemical assays with the antibodies to surface markers of lymphocytes L26 and UCHL-1 indicated that the lymphoplasmacellular proliferation was not neoplastic but probably represented an immune reaction of the host.