The invasive fungal infection (IFI) is the most common cause of mortality related to autologous stem cell transplant. Taking into account that Saprophytic Aspergillus is usually acquired by inhalation, to protect the bronchial tree just before the tissue invasion is quite attractive. In haematologic patients, as well as those ones subjected to an Allogeneic haematopoietic progenitor cell transplant, there is another group of patients at high risk of Invasive Pulmonary Aspergillosis (IPA). These are those patients with acute myeloid leucemia (AML), submitted to induction, intensification or consolidation polychemotherapy. The IPA incidence rate in these patients, whenever during their evolution, reaches 18-20%, with usual treatments. Furthermore, unlike allogeneic haematopoietic progenitor cell transplant patients, neutropenia was the only IPA risk factor. Nowadays, pharmacologic prophylaxis against IPA, in patients with allogeneic haematopoietic progenitor cell transplant and patients affected by AML in induction or intensification therapy is far from being optimal, because of problems related to tolerance and drug interactions .