DISCUSSION: ABPA is found almost exclusively with asthma or CF. The pathogenesis involves a hypersensitivity reaction following respiratory tract colonization by A. fumigatus. Diagnostic criteria include a combination of radiologic findings, symptoms, and serologic testing as well as a history of asthma or CF (1,2). Our patient met many of these criteria: cavitary lung lesions, central bronchiectasis, eosinophilia, elevated IgE, precipitating antibodies to Aspergillus, and growth of Aspergillus from multiple respiratory specimens (sputum and BAL), but did not have asthma or CF. At baseline he had a normal eosinophil count and onset of his acute illness started shortly after finishing successful treatment for pulmonary MAC infection.