During a 25-year period 168 adults and 111 children in Copenhagen County were treated for acute epiglottitis. Four patients, two children and two adults died, of these the two children and one adult had a cardiac arrest on arriving at the hospital. Most children were treated by nasotracheal intubation while only some adults required nasotracheal intubation in order to secure the airway. Our data indicate that intubation of adults with epiglottitis is technically more difficult than in children. The fibrelaryngoscope, a new diagnostic tool, is advocated, and was in this study used to establish the diagnosis in 12 unclear cases of acute epiglottitis. The incidence of acute epiglottitis in children was calculated at 3.2/100,000 with a minor annual variation. As vaccination against Haemophilus influenzae type b becomes more common, the incidence will probably be markedly reduced, maybe even eradicated in children, but in adults the same reduction cannot be expected as the causative agent in this group is less frequently Haemophilus influenzae type b.