• Infections of the central nervous system in patients with the acquired immunodeficiency syndrome are common. Of the many microorganisms that have been implicated, infection with Aspergillus is rare. We describe three patients with Aspergillus infection of the nervous system. Two patients had cerebral lesions due to Aspergillus flavus, and one patient had Aspergillus fumigatus infection of the spinal cord. Diagnosis of the infections was difficult, and therapy appeared to be ineffective.