Mantle cell lymphoma (MCL) is a rare form of non-Hodgkin lymphoma characterized by clonal proliferation of follicular mantle zone B lymphocytes. It is caused by abnormal chromosomal translocation t(11;14) resulting in aberrant expression of cyclin D1. This leads to activation of anti-apoptotic pathways and abnormal proliferation of MCL cells. Patients can present with an indolent course or a fulminant disease with short overall survival. The disease frequently involves extranodal organs, but rarely manifests with neurological symptoms. We report a rare case of aberrant CD5-negative MCL presenting with aseptic meningitis.