Superior laryngeal nerve (SLN) is a branch of vagus nerve in the neck. It is further divided into internal and external branches. Both components are equally important in the preservation of laryngeal function which is to protect the lower airway from intrusion of any foreign material, as well as producing good quality of voice. The internal branch supplies mucosal sensation of the supraglottic region down to the level of vocal cord. Thus, its function is very critical in sustaining the cough reflex as an afferent fiber to detect any penetration to the larynx. However, this branch (internal laryngeal nerve) is less susceptible to injury during thyroid surgery.