Pneumonia in children is encountered frequently in daily practice, however, it remains a diagnostic challenge. Croup is the most common infectious cause of upper airway obstruction in children. Both of these respiratory processes occur during the school year and may present in children who develop fever, cough, and respiratory distress during the school day. Using a case-based approach, this chapter will review differential diagnosis, symptoms, exam findings, classification, and management based on severity of clinical presentation. Each section will also discuss return to school.