In neutropenic patients, one way of improving invasive pulmonary aspergillosis (IPA) prognosis is an earlier initiation of the antifungal treatment. We report our experience with 36 cases of IPA in 35 patients with haematological malignancies. When aspergillosis was diagnosed, all but 2 patients were neutropenic (PMN < 500; median duration = 20 days). The most frequent clinical signs were cough (100%), chest pain (78%) and haemoptysis (58%). Before the diagnosis of IPA, Aspergillus antibody test was positive in 60% of cases. A thoracic CT-scan was performed in 23 patients and demonstrated highly suggestive images in 22 cases (96%) with presence of CT halo sign (n = 13) or CT air-crescent sign (n = 9). Moreover, Aspergillus antigen test was positive in 13 of 28 tested patients. IPA diagnosis was determined to be definite in 23 cases and probable or possible in 13 cases. Thirty-five patients were treated: in 3 cases with amphotericin B (2 failures) and in 32 cases with itraconazole (7 failures and 25 successes or improvements). In 7 cases (including 5 emergencies) surgical resection was successfully combined with the medical treatment. In neutropenic patients with fever, we consider that thoracic CT-scan and repeated biological tests (Aspergillus antibody and antigen tests) can be used to establish the diagnosis of aspergillosis. Early treatment with itraconazole and surgical resection appears to improve prognosis.