AT AGE 3 WEEKS, a full-term newborn developed recurrent cough and stridor without other signs of respiratory distress. She had no feeding problems and was thriving. At age 6 months, inspiratory and expiratory stridor became more pronounced, and she developed dyspnea. A chest radiograph was obtained to evaluate the airway, upper mediastinum, and esophagus (Figure 1). The vertebrae were normal. Magnetic resonance imaging followed (Figure 2). Surgery was performed, and the stridor and respiratory distress ceased immediately after surgery.