A 9-year-old female rose-breasted cockatoo (Eolophus roseicapilla) was presented for a humeral fracture. At presentation, the bird was severely lethargic and obese. On physical examination, an open right humeral fracture, healed left ulnar fracture, and intertarsal joint swelling were present. Results of hematologic testing and biochemical analysis revealed severe leukocytosis with heterophilia and increased creatine kinase and aspartate aminotransferase activities consistent with musculoskeletal lesions. Radiographs confirmed a right humeral fracture and showed severe polyostotic lytic and expansile lesions of the appendicular skeleton, as well as an enlarged hepatic silhouette. Surgical repair of the fracture was attempted, but the bird died during the procedure. Postmortem examination revealed severe bone deformities involving the fractured humerus, both ulnas, and the left tibiotarsus. Histologic findings were consistent with multiple intraosseous lipomas of the long bones and severe hepatic lipidosis. To our knowledge, this is the first report of multiple intraosseous lipomas in a bird.