A 62-year-old man had progressive visual loss from neurosyphilis while his optic disks appeared atrophic. At no time was there evidence of inflammation of the globe or of either optic disk. The presence of an extremely high IgG index and five oligoclonal bands in the cerebrospinal fluid indicated that the central nervous system was synthesizing antibody specific to Treponema pallidum. Recent investigations indicate that much larger doses of penicillin are necessary for adequate treatment of neurosyphilis than have been recommended previously.