Herpes simplex virus (HSV) typically causes mucocutaneous disease, encephalitis, and acute men ingitis. There have been no previous reports of chronic meningitis due to this virus. A case of chronic meningitis due to herpes simplex virus type 2 (HSV-2) in a previously healthy 35-year-old woman whose predominant symptoms were headache and meningism without fever is described. Analysis of cerebrospinal fluid (CSF) revealed a lymphocytic pleocytosis, elevated protein, and hypoglycorrhachia. The diagnosis of herpes simplex meningitis was supported by the detection of HSV-2 DNA in CSF by polymerase chain reaction and by intrathecal production of HSV-specific antibody. The patient recovered after treatment with intravenous acyclovir and glucocorticoids.