Avian aspergillosis is reported in several avian species, with Aspergillus fumigatus as the main aetiological agent. Predisposing factors such as starvation, thermal stress, migratory stress, primary infectious disease or toxicosis may play a role. Eight cases of disseminated aspergillosis in free ranging seagulls sheltered at C.R.U.M.A. (Centro Recupero Uccelli Marini e Acquatici, Livorno, Italy) with different clinical histories are presented. The infection was demonstrated by cultural and histological methods from lesions of all birds, and the presence of airborne A. fumigatus viable elements ranging from 450 to 525 CFU/m(3) inside and outside the shelter by means of a surface air sampler (SAS) Super-90 was also assessed. The role of this fungal species as an opportunistic factor in the captivity of seagulls is considered and some control measures, such as a clean and stress free environment and the use of antifungal drugs are suggested.