Although viral croup is the most common form of airway obstruction in children 6 months to 6 years of age, there is debate regarding medical care for the hospitalized patient. A complete review of the English-language literature from 1960 to 1988 was performed, using both manual and Medline searches. Critical review shows that laryngotracheitis and spasmodic croup, previously emphasized in the literature as having distinct etiologies, most likely are two ends of a broad spectrum in the clinical presentation of a single disease. Critical assessment of all prospective randomized double-blind placebo-controlled trials reported during the study period shows that there is little information on the use of humidified air or supplemental oxygen, that racemic epinephrine hydrochloride is of well-demonstrated efficacy, and that dexamethasone phosphate at a dose greater than 0.3 mg/kg is effective in decreasing the length and severity of respiratory symptoms associated with viral croup.