A 13-year-old Quarter Horse mare was presented to the Ontario Veterinary College Teaching Hospital with chronic progressive respiratory noise and exercise intolerance. Severe respiratory stridor associated with a laryngeal mass was seen on upper airway endoscopy. Ultrasonography revealed an intra-cartilagenous mass and allowed for a guided biopsy. Histological analysis of the mass characterised a neuroendocrine tumour and the mare was subjected to euthanasia due to the poor prognosis. Ultrasound examination was paramount in making the diagnosis and facilitating the biopsy. To our knowledge, neuroendocrine tumours have not previously been reported in the equine larynx.