The acquired immunodeficiency syndrome (AIDS) appears to alter the course of syphilis and particularly neurosyphilis. We report the case of an HIV-positive patient with two CNS lesions due to vascular complications of neurosyphilis of the meningovascular type, 18 months after he had developed a penile chancre. On admission, CT scans were inconsistent with cerebral toxoplasmosis or CNS lymphoma. At necropsy, histopathological examination showed typical Heubner's endarteritis of the basilar and posterior cerebral arteries. In AIDS patients, superadded meningovascular syphilis must be suspected, especially when CT scanning reveals the presence of multi-focal, low density lesions with the particular characteristics of infarction.