Four patients with aspergillosis of the central nervous system collected in less than two years are reported. Three patients had hematologic malignancies (acute myelogenous leukemia, Hodgkin's disease) and were treated with corticosteroids and chemotherapy. One patient received antimicrobial agents fort a post operative meningitis (after acoustic neuroma surgery). Analysis of these cases and review of literature available us to point out the increased frequency of invasive and cerebral aspergillosis particularly in immunocompromised hosts treated by cytotoxic drugs or broad spectrum antibiotic therapy. Diagnosis is very difficult because: --there are non specific radiologic features for aspergillus granuloma, abscess, aneurysm or meningitis, --blood and cerebrospinal fluid cultures are invariably negative, --serologic tests have limited value in immunosuppressed patients (poor capacity to elaborate antibodies). Diagnosis can be made only by surgical biopsy who isolate fungal elements. However diagnosis in greatest cases is only made at autopsy. Treatment consist by antifungal drugs administered intravenously and surgery when it is possible. Prognosis of cerebral aspergillosis is very poor and mortality rate very high about 70%.