Disseminated aspergillosis due to Aspergillus terreus was diagnosed in a young pigeon kept by a bird fancier. The fungus was isolated in heavy growth from the infected tissues on Sabouraud medium at 37 degrees C. Microscopic examination of the squeeze preparation of the air sacs revealed the presence of typical conidiophores of an Aspergillus sp. Histologically, branched, septate hyphae morphologically indistinguishable from Aspergillus were detected in the air sacs and lungs. The clinical, mycological and pathological findings are discussed. The role of A. terreus as an opportunistic pathogen should be studied in various clinical conditions of mammals and avians.