A case of cerebral aspergillosis in a 69-year-old diabetic man is reported. The disease, initially presenting as headache and vertigo, was caused by Aspergillus fumigatus. Seven CSF specimens were examined. The main findings included decreased glucose and increased protein concentrations, leukocyte reaction and one positive culture for A. fumigatus. Neuropathological examination revealed granulomatous leptomeningitis and typical fungal hyphae. The process probably lasted for more than 1 year and was an important contributing factor to two brain stem infarcts.