We describe three patients with benign recurrent aseptic meningitis (Mollaret's meningitis). For one of these cases, the episodes of meningitis were associated with herpetic outbreaks. Mollaret cells, which are a hallmark of Mollaret's meningitis, were present in the CSF from two of the three patients. In all cases, herpes simplex virus type 2 DNA was present in the CSF during the acute illness as detected by polymerase chain reaction amplification, although viral cultures from CSF were all negative. Herpesviruses, notorious for frequent and sporadic recurrence, are ideal candidates for the cause of Mollaret's meningitis.