Invasive pulmonary aspergillosis (IPA) is the most common fungal pulmonary infection in severely immunocompromised patients. Aspergillus species are commonly isolated from the soil, plant debris, and the indoor environment, including the hospital. Phagocytosis is the main host defense against Aspergillus conidia and hyphae. The diagnosis of IPA is based on clinical, radiological, and mycological data. Clinical signs have a low specificity. The most typical computed tomographic (CT) findings are nodules with or without the halo sign or the air crescent sign. Sensitivity of microscopy and culture of noninvasive collected samples is low. Galactomannan and nucleic acid detection in serum or in bronchoalveolar lavage (BAL) fluid help to confirm the diagnosis. Crude mortality is high and strongly correlated with the underlying condition, stage of the underlying disease, and extension of the aspergillosis. Optimal therapeutic strategies include the prevention of contamination in patients at high risk, early initiation of antifungal therapy, surgery in some instances, and, importantly, treatment of the underlying condition to restore whenever possible a certain degree of immunocompetence. Voriconazole has demonstrated better efficacy and safety than amphotericin B deoxycholate. The improved survival observed with voriconazole makes it a new reference for the first-line therapy of IA. Lipid formulations of amphotericin B, caspofungin, micafungin, and posaconazole are other therapeutic options in the event of failure of or contraindication to voriconazole. The main indication for surgery is prevention of severe hemoptysis when the lesion is adjacent to a large vessel.