The recurrent laryngeal nerve is a branch of the vagus nerve (the tenth cranial nerve) which supplies the larynx (voice box). It is called "recurrent" as the left branch initially descends into the mediastinum, then passes under the main left bronchus and moves upward again to the throat.

The nerve is best known for its importance in thyroid surgery, as it runs immediately posterior to this gland. If it is damaged during surgery, the patient will have a hoarse voice. Nerve damage can be assessed by laryngoscopy , during which a stroboscopic light confirms the absence of movement in the affected side of the vocal cords.

Similar problems may also be due to invasion of the nerve by a tumor.

Galen was the first to describe the clinical syndrome of recurrent laryngeal nerve paralysis.