Allergic bronchopulmonary aspergillosis (ABPA) develops as the result of a hypersensitivity reaction to fungi of the genus Aspergillus. Clinical and radiological presentation can be atypical, requiring a high degree of suspicion on the part of the physician who treats such patients. We report the cases of two patients with APBA in whom the form of presentation--with few asthma symptoms, images showing lobar atelectasia and hilar adenopathy--led to an initial suspicion of lung cancer.