Invasive aspergillosis generally occurs in patients with hematologic malignancies, neutropenia or other severe derangements of host defense. An adult patient without such a predisposition, and without a previous history of susceptibility to infections, had rapidly progressive respiratory failure associated with repeated growth of Aspergillus fumigatus on culture of sputum and bronchoscopy specimens. At autopsy he proved to have invasive pulmonary aspergillosis.