The larynx is a semi-rigid valve compromising three major and two smaller hyaline cartilages and striated muscles that separate the upper and lower respiratory tracts. The vocal ligaments in the lumen of the larynx extend from the vocal processes of the arytenoids to the ventral midline, and the vestibular ligaments extend from the cuneiform processes to the ventral midline. The larynx is lined with stratified mucosa , folds of which protrude into the lumen of the cylinder over these ligaments; these are the vocal and vestibular folds, respectively. The resultant crypts formed between the two folds are the laryngeal ventricles. The ventricles are absent in cats. The chapter considers Anatomy of the larynx; Laryngeal function; and Diseases of the larynx.