Episodic laryngeal dysfunction (ELD), also known as paradoxical vocal cord dysfunction or laryngeal dyskinesia, is characterized by abnormal closure of the vocal cords during inspiration (and sometimes at the very start of expiration). It can manifest in different ways depending on the patient's age. In the newborn, it is usually associated with stridor restricted to the inspiratory breath following crying, and the natural history is always one of rapid resolution. Occasionally, a more severe form presents with intense dyspnea and marked inspiratory stridor in a baby that usually has extensive gastroesophageal reflux which has not been treated adequately enough to improve the dyspnea or the associated vasovagal attacks. A tracheotomy may be necessary. It is rare for this disease to present between the ages of 2 and 8 years. Thereafter, it may present as a form of pseudo asthma resistant to bronchodilators and anti-inflammatory drugs. The dyspnea can be very severe and lead the family to seek hospital admission, at least during the initial episodes. There is a female preponderance. The key to making the diagnosis is the complete reversibility of the patient's symptoms when they are distracted. Exertion asthma can be mimicked by forms of ELD that occur only by effort (apart from the profile of the lung function tests). There may be significant gastroesophageal reflux. Medical intervention (hospitalization and tracheotomy) must be avoided, treatment being essentially behavioral. Finally, some cases of paradoxical adduction of the vocal cords have been described with the use of neuroleptics, brain stem compression, cortical lesions and, much more rarely, motoneuron disease. This diagnosis requires a high index of suspicion, particularly in patients with asthma whose presentation or clinical course with treatment is atypical.