A 10 year-old female Red Panda (Ailurus fulgens styani) was diagnosed with a cranial mediastinal mass on June 27, 2007 via thoracic radiography during routine annual physical examination. Previous medical history relative to this finding was unremarkable. At the time of diagnosis this panda did not exhibit clinical signs of disease. Physical examination was unremarkable. Abdominal ultrasound revealed no significant abnormalities. The panda remained asymptomatic over the next two months. Additional diagnostics included hematology, thoracic radiographs, thoracic ultrasound, ultrasound-guided fine needle aspiration of the mediastinal mass, and computed tomography of the thorax. No evidence of metastasis was identified and approximately 2 months after initial diagnosis a midline sternotomy was performed to remove the mass which was later diagnosed as a benign thymoma. The patient made a complete recovery from surgery and returned to public exhibit.