We have obtained physiologic and psychiatric evaluations on five subjects with episodic laryngeal dyskinesia (LD) and compared them with three patients with expiratory laryngeal stridor and asthma (ELS), and five with chronic asthma (CA). Laryngoscopy confirmed adduction of the vocal cords. Diminished inspiratory flow rates with an expiratory/inspiratory ratio of 1.5 to 3.3 was demonstrated by flow volume studies. Flows improved strikingly while breathing an 80 percent helium/20 percent oxygen mixture. Patients with LD showed varying degrees of depression and sought some form of secondary gain. A histrionic personality, conversion or factitious disorders are not an essential part of this syndrome. Tracheostomy may seldom be necessary in the managing of the acute crisis of LD. Reassurance, oxygen, intermittent positive pressure, and sedation may be sufficient. Mildly depressed patients decreased the frequency and severity of wheezing episodes after receiving reassurance and a clear explanation of ventilatory mechanics.