In medicine, laryngospasm is an uncontrolled/involuntary muscular contraction (spasm) of the laryngeal cords. The condition typically lasts less than 60 seconds, and causes a partial blocking of breathing in, while breathing out remains easier. It may be triggered when the vocal cords or the area of the trachea below the cords detects the entry of water, mucus, blood, or other substance. It is characterized by stridor and or retractions. Some people suffer from frequent laryngospasms, whether awake or asleep. In an ear, nose and throat practice, it is typically seen in people who have silent reflux disease. It is also a well known, infrequent, but serious post-surgery complication.

In some individuals this can occur spontaneously or as a result of reflux or impaired swallowing. It is also a complication associated with anesthesia. The spasm can happen often without any provocation, but tends to occur after tracheal extubation. In children, the condition can be particularly deadly, leading to cardiac arrest within 30–45 seconds, and is a possible cause of death associated with the induction of general anesthesia in the paediatric population.