The cricoarytenoideus lateralis muscle (CAL) is an adductor of the arytenoids and, although not directly involved in the pathogenesis of recurrent laryngeal neuropathy as the abductor cricoarytenoideus dorsalis muscle (CAD) does; it is the first to experience a neurogenic atrophy. On fifteen geldings and fifteen females weighing about 500 kg and aged between 3 and 9 years an ultrasound examination of the larynx was performed, in order to assess shape, size and echogenicity of CALs. The average width and thickness of the muscle were respectively 0.95 and 0.79 cm, the former being the most reliable. No differences have been found in relation to sex, age or between right and left muscle. Focal calcifications of thyroid cartilage prevented visualization of the muscles especially in female animals.