Pulmonary carcinoma was diagnosed in a 14-year-old male Moluccan cockatoo (Cacatua moluccensis) presented for sudden onset of ataxia of the pelvic limbs lasting several hours. On physical examination, the cockatoo had paraparesis of both legs and a reduction in pectoral muscle mass. The bird responded to initial supportive therapy; however, its clinical condition deteriorated over a 3-week period. Histopathologic examination revealed pulmonary carcinoma with intrapulmonary metastases as well as metastases to the vertebral column and right humerus.