Syphilis and its consequent central nervous system sequelae remain clinical problems, especially when presenting in the unfamiliar acute meningeal forms of syphilitic meningitis and meningovascular syphilis. The diagnosis of neurosyphilis of all types depends on evaluation of spinal fluid reactivity as evidenced by pleocytosis and increased protein content with reactive serology. The cerebrospinal fluid is always abnormal in active disease, and only active disease responds to treatment. Penicillin remains the drug of choice for all forms of neurosyphilis, but disease progression has been frequently reported following the use of penicillin G benzathine. Documentation of cerebrospinal fluid resolution over the months following penicillin therapy is required to confirm curative treatment.