--To assess the efficacy of intrathecal therapy with tetanus antibody (antitetanus equine serum or human tetanus immune globulin) in neonatal and adult tetanus using meta-analytical techniques.--Clinical trials identified by searching MEDLINE and by reviewing bibliographies of published articles.--Studies in English with concurrent controls treated without intrathecal therapy.--Data were extracted by one author and verified by the second; conflicts were resolved by discussion.--No major treatment effect was found in neonatal tetanus when all studies were considered. A benefit was suggested for antitetanus equine serum in adult disease, but this finding should be accepted with caution. Subgroup analyses were limited in power. Methodological difficulties in neonatal and adult trials were common and safety has not been established.--Intrathecal therapy for tetanus with either antitetanus equine serum or human tetanus immune globulin is not of proven benefit and should only be given in the context of well-designed, controlled trials.