Allergic bronchopulmonary aspergillosis (ABPA) is a complex immune hypersensitivity reaction to Aspergillus fumigatus, usually complicating the course of patients with asthma and cystic fibrosis. The common radiological manifestations encountered are fleeting pulmonary opacities, bronchiectasis and mucoid impaction. Uncommon radiological findings encountered in ABPA include pulmonary masses, perihilar opacities simulating hilar adenopathy, miliary nodules and pleural effusions. Herein, we describe a 22-year-old female patient who presented with acute hypoxaemic respiratory failure secondary to left lung collapse, which necessitated rigid bronchoscopy for management. On further evaluation, she was diagnosed to have ABPA. This is the first documented report of ABPA presenting as acute hypoxaemic respiratory failure secondary to lung collapse.