A four-year old female Long-legged Buzzard with 4x5,5x3 cm fluctuant lesion under the left wing was brought to the Surgery Department of Erciyes University, School of Veterinary Medicine, clinically extremely emaciated and weak. The fluctuant mass was surgically removed but the Long-legged Buzzard died due to its poor condition. At necropsy, grey-white-coloured necrotic lesions in ileum and spleen, and yellow-brown-coloured hard nodules in the which one lung were observed. Samples from the mass, spleen, intestines, and lungs were examined histologically. Bacterial clusters within and around the necrotic mass were surrounded by giant cells, followed by cell infiltrations with heterophils and macrophages, and finally covered with a fibrous tissue capsule. Also observed were spores, hyphae, and conidiophore structures characteristic of fungi in bronchial lumina and surrounding mesobronchus as well as lesions similar to that of the lung. For the differential diagnosis, Ziehl-Neelsen and Gridley's staining were performed. Gram (+) and acid-fast bacteria in the mass from the wing, spleen, intestines, and lungs, and also hyphae and spores of fungi in the lung were identified. In the bacteriological examination, Mycobacterium sp. was isolated after inoculation into Lowenstein-Jensen medium containing glycerin. In addition, Aspergillus fumigatus was identified and isolated from lung.