Aspergillosis is a disease caused by the filamentous fungus Aspergillus spp. with a spectrum of clinical presentation that includes invasive and noninvasive forms. The invasive clinical presentation of aspergillosis most frequently affects people with compromised immune systems. In patients with oncohematologic pathology, invasive lung aspergillosis is a significant opportunistic mycosis, because it occurs frequently and has a major impact on morbidity, mortality, and high costs. The global problem of antimicrobial resistance, to which improper use of antifungals contributes, has put Aspergilus spp. in the spotlight, so it is important to generate guidelines for guidance in the proper use of antifungals in the management of invasive lung aspergillosis, to obtain better clinical outcomes and promote rational use of antifungals. This guideline contains recommendations for diagnosing and treating invasive lung aspergillosis in patients with oncohematologic disease, based on evidence and defined through a participatory process of expert consensus, for the Latin American context.