Infections of the upper airways are a frequent cause of morbidity in children. Viral laryngotracheobronchitis (croup) is the most common cause of stridor in children and usually has a self-limited course with occasional relapses in early childhood. Epiglottitis has become rare in developed countries with the advent of universal vaccinations against Haemophilus influenzae. It can be rapidly fatal, however, if not promptly recognized and appropriately managed. This article reviews the pathogenesis, epidemiology, clinical presentation, diagnosis, and management of these pediatric upper airway infections.