Among forty-six patients with neurosyphilis, seen over a ten-year period, six had features highly suggestive of syphilitic cerebral vascularitis. The carotid distribution was involved in five patients and the posterior cerebral artery in one. As exemplified by these six observations, syphilitic arteritis should be considered when an ischemic stroke occurs with no apparent etiology. The fluorescent treponemal antibody adsorbed test (FTA-ABS) in the cerebrospinal fluid is the most reliable and the most specific laboratory test for the diagnosis of neurosyphilis.