Three types of acute obstructive laryngitis in children are distinguished: 1. Acute supraglottic laryngitis (Epiglottitis acuta): The usual causative organism is Hemophilus influenzae, type B. Characteristic findings include a swollen red epiglottis. Treatment is based on Ampicillin, Solucortef (hydrocortisone-sodium succinate) i.m., air humidification, intravenous infusions and airway protection (tracheotomy or intubation). From 1958-1967, 68 children were treated, of whom boys were twice as commonly affected as girls. In about 80% of cases, tracheotomy was still found necessary. 2. Acute subglottic laryngitis: Mucosal swelling in the subglottic space causes a clinical picture which initially is common to several groups of deseases. In allergic subglottic edema, a pale "pillow-shaped" swelling occurs which responds favorably to antiallergenics and cortisone. In contrast, infectious swelling is partially caused by the infiltration of inflammatory cells. Parainfluenzae virus was isolated in 60% of these cases at our hospital. During the period studied, 2,741 cases were treated, of whom boys were 3.3 times more frequently affected than girls. The use of Solu-cortef i.m. has decreased the tracheotomy rate from 12% to 0. 3. Acute laryngotracheobronchitis: In this disease process, the initial infection is attributed to a virus, with the infected mucosa secondarily invaded by bacteria. The clinical course is prolonged when compared to subglottic laryngitis, and the general condition seriously affected. Both expiratory and inspiratory stridors occur. Tracheotomy is usually required, with viscous crusts removed by bronchoscopy. Respirator treatment is also often required. Fourteen children have been treated, of whom two have died.