Birds are routinely exposed to this fungus and only rarely become pathogenic and the lower respiratory tract is most severely affected by inhalation rout. There have been some recent reports about respiratory aspergillosis in ostrich (Kyoung 2001, Marks et al 1994). Aspergillus spp usually cause disease under condition of stress, immunosupression, and prolonged treatment with antibiotics or massive exposure to the microorganism. Clinical signs of aspergillosis in ostriches are weight loss, lethargy and dyspnea (Kyoung 2001). Other less common forms of aspergillosis in birds are encephalitis, ophthalmitis, osteomyelitis, dermatitis and systemic form (Fitzgerald & Moisan (1995). A fumigatus was isolated in some cases of respiratory aspergillosis (Campbell (1986). It has been reported that aspergillosis was observed in ostriches in the late 19th and early 20th centuries, but is relatively uncommon today (Terzich &. Vanhooser (1993). This is the first case report of aspergillosis due to A ftnigatus in Iran. The ostriches of this report had received chloramphenicol and enrofloxacin for a long time (45 days) so these drugs may have been the cause of the pulmonary aspergillosis.