Two cases of invasive aspergillosis (IA) in immunocompetent patients with a fulminant fatal outcome are reported. Both patients were elderly and had a history of chronic lung disease treated with prolonged inhaled corticosteroids and a short course of systemic corticosteroids. They presented with dyspnea and fever, their respiratory function deteriorated rapidly, and they died 7 days after admission. Aspergillus fumigatus was cultured from respiratory samples. IA was confirmed in one case by necropsy that showed diffuse bilateral necrotizing pneumonitis and myocarditis. In the other case, IA diagnosis was established by thoracic CT scan plus detection of Aspergillus antigen in two blood samples. These two cases demonstrate that short-term corticosteroid therapy in immunocompetent patients with underlying chronic lung conditions is a risk factor for IA, and that its evolution can be fulminant.