Bronchial diseases are common in children, and are usually associated with disturbances of aeration. This article briefly summarizes the embryological development and respiratory physiology pertinent to pediatric bronchial diseases. Current diagnostic imaging tools are discussed, with an emphasis on CT, which can demonstrate bronchial pathology such as bronchial obstruction and bronchiectasis in larger bronchi, as well as indirectly show the peripheral physiologic consequences of bronchial disease, such as alterations in aeration. Computed tomography measurements of lung attenuation may aid in diagnosis in problematic cases. Diseases that affect the pediatric airways at different ages are reviewed. Knowledge of these entities is important for accurate interpretation of imaging studies.