A 13-year-old male salmon-crested cockatoo (Cacatua moluccensis) was presented for evaluation of a right thoracic limb mass. A 5 × 5-cm mass was palpated within the right humeral middiaphysis, extending to the radiohumeral joint. On computed tomography examination, the mass extended from the right humeral bone into adjacent soft tissue; pulmonary metastasis was not observed. To obtain adequate surgical margins with no histologic evidence of neoplastic cells, complete amputation of the right wing at the scapulohumeral joint was performed. The tumor was diagnosed as a primary mucinous adenocarcinoma arising from the respiratory epithelial lining of the medullary cavity of the right humerus. The cockatoo recovered well from surgery and was reported to be in good health 8 weeks after surgery.