Invasive pulmonary aspergillosis usually occurs in patients with severe granulocytopenia or defects of cell-mediated immunity secondary to cytotoxic chemotherapy or high-dose corticosteroids, but it is an unusual opportunistic infection in patients with AIDS. Eleven cases of Aspergillus pulmonary disease were diagnosed in HIV-infected patients from January 1985 to December 1992, in the Department of Infectious Diseases of the Catholic University. Four patients had invasive pulmonary aspergillosis, six probable pulmonary invasive aspergillosis and one allergic bronchopulmonary aspergillosis. Fiberoptic bronchoscopy with bronchoalveolar lavage was confirmed to be an useful tool for the diagnosis of pulmonary aspergillosis in AIDS patients. The response of aspergillosis to therapy, either amphotericin B or itraconazole, has usually been poor. It is possible to speculate that the longer survival of AIDS patients and the latter development of other functional immunological abnormalities related to HIV infection may allow the appearance of opportunistic infection, such as pulmonary aspergillosis, different from those more often observed.