A ten-year-old beef suckler cow was referred to the Scottish Centre for Production Animal Health & Food Safety of the University of Glasgow, because of facial swelling in the region of the right maxilla. The facial swelling was first noticed three months earlier and was caused by a slow growing oral mass which contained displaced, loosely embedded teeth. The radiographic, laboratory and clinicopathological findings are described. Necropsy, gross pathology and histological findings confirmed the mass as a maxillary osteosarcoma.