Invasive aspergillosis is a disease that affects immunosuppressed patients, in close relationship with the presence and duration of neutropenia. Although formerly included among the AIDS definition criteria, it was thereafter dropped out because of its very low prevalence. We describe here four cases of invasive aspergillosis in HIV infected patients, diagnosed at our institution. Three patients presented with invasive pulmonary aspergillosis, including one patient with chronic ulcerative pulmonary aspergillosis. The fourth patient developed aspergillosis of the brain. Taking into account the difficulties in establishing a diagnosis of this infection before death (most of published cases were from autopsy reports) and because of the paramount importance of early diagnosis for improving survival, we support the use of invasive pulmonary aspergillosis diagnostic criteria in a similar way as used in patients suffering lymphoproliferative disorders. Although classic treatment of this infection is based on the use of amphotericin B (with or without 5 fluorocytosine), the potential usefulness of itraconazole (a new imidazole drug) has to be considered. In spite of the low number of published cases, we believe that invasive aspergillosis among HIV infected patients has to be included as a likely diagnosis, specially in view of the prolonged survival and widespread use of cancer chemotherapy in this population.