Ultrafast computed tomographic (CT) evaluation of the airway can be performed with either 50-msec low-resolution images (cine CT) or 100-msec high-resolution images (high-resolution CT). To determine the best imaging strategy for ultrafast CT of the pediatric airway, the authors prospectively compared ultrafast CT and endoscopy in 20 children. Both studies were performed in 11 patients; cine CT alone was performed in six and high-resolution CT alone in three. Six patients had normal anatomy. Six patients had focal tracheal stenoses, four had tracheomalacia or laryngomalacia, one had a laryngoesophageal cleft, one had irregularity and narrowing in the subglottic area, one had laryngeal papillomas, and one had focal stenosis with stoma granuloma. Cine CT results agreed with those of endoscopy in 10 of 17 cases. In five cases focal stenosis was misinterpreted with cine CT as tracheomalacia. High-resolution CT results agreed with those of endoscopy in 10 of 14 cases. The results of a technique that combined high-resolution CT for the entire airway and cine CT at selected areas agreed with those of endoscopy in 10 of 11 cases; only a tracheoesophageal cleft was missed with the combined technique. For the greatest diagnostic accuracy with ultrafast CT in evaluation of the pediatric airway, both cine and high-resolution modes should be used.