Allergic bronchopulmonary aspergillosis (ABPA) is a multifaceted immune hypersensitivity reaction occurring in the lungs and bronchi, triggered by exposure and colonization of Aspergillus species, commonly Aspergillus fumigatus (A. fumigatus). It typically affects individuals who are immunocompetent but predisposed, such as those with bronchial asthma and cystic fibrosis. Diagnosis involves various methods including chest radiography, computed tomography, identification of eosinophilia, elevated serum IgE (immunoglobulin E) levels, and immunological tests for Aspergillus antigen. Left undiagnosed and untreated, ABPA can advance to bronchiectasis and/or pulmonary fibrosis, leading to significant morbidity and mortality.