This is a prospective treatment study of 86 patients with tuberculous meningitis admitted to the Abbassia Fever Hospital Cairo, Egypt. The causative organism was cultured from the cerebro spinal fluidin 47 patients, was identified by Zeihl Nelson stain in five and in the remaining 34 patients the diagnosis was based on the clinical course and changes in the CSF chemistry and cell count. The data indicate that ethambutol can be used as a companion drug to INH and streptomycin in the treatment of the disease and that the mortality is directly dependent on the state of consciousness upon initiation of therapy.