The neurological complications of Epstein-Barr virus infection include viral meningitis, encephalitis and neuromuscular complications. The introduction of cerebrospinal fluid polymerase chain reaction for Epstein-Barr virus DNA has improved diagnosis of these conditions and of primary central nervous system lymphoma in acquired immune deficiency syndrome, and has enabled cerebrospinal fluid monitoring of therapy. Prognosis remains good for most Epstein-Barr virus-related neurological complications; for primary central nervous system lymphoma in acquired immune deficiency syndrome the prognosis is still poor.