Objective:To investigate clinical, pathological and mycological findings in canaries, in which pox lesions and Aspergillus fumigatus (A. fumigatus) infection were observed simultaneously. Methods:This study was performed on a breeding colony (about 100 canaries) affected by fatal wasting disease. Necropsy was undertaken on 10 severely affected canaries, and gross lesions were recorded. Samples from intal organs displaying lesions were obtained for histopathological evaluation. Tracheal swap samples of intal organs of the all infected animals with lesions at necropsy were cultured in Sabouraud Dextrose Agar for mycological examination. Results: At necropsy, caseous foci were determined in the lungs, on the air sacs, liver, spleen, heart. Swelling of the eyelids, diffuse hemorrhages in the subcutaneous tissue with small papular lesions of the skin were other typical necropsy findings. Histopathologically, pathognomonic eosinophilic intracytoplasmic inclusion bodies, which called Bollinger bodies, in both skin cells and vacuolated air way epithelial cells confirmed canary pox infection. Moreover, histopathological examination of the white-yellowish caseous foci revealed necrotic granulomatous reaction consisting of macrophages, heterophil leukocytes and giant cells encapsulated with a fibrous tissue. After the culture of the tissue samples, the formation of bluish green colonies confirmed A. fumigatus infection. Conclusions:Canary pox has been known as the disease that can result in high losses in a short time, as a re-emerging disease that has not been present during recent years in canary flocks in Iran. So, the current paper provides useful information to prevent misdiagnosed of canary pox disease which can cause secondary mycotic infection.