Acute infections of the respiratory tract are common in pediatric patients. Respiratory disease is the leading cause of hospitalization in children less than 4 years of age and is responsible for many physicians' office and emergency department visits.(1) The severity of upper respiratory tract infection ranges from mild, self-limited disease to potentially life-threatening airway obstruction. The prepared clinician can often make a diagnosis based solely on the history and physical examination, using radiographs and laboratory examinations to aid in diagnosis when the clinical picture is unclear. At times, airway collapse is imminent, and the clinician must proceed directly to endoscopy for definitive diagnosis and airway protection. This article will discuss the pathogenesis, clinical presentation, and management of epiglottitis, croup, and bacterial tracheitis in the pediatric population.