Starting with the mouth and nose, airways are the part of the respiratory system in which air is transported to the lungs. If any of these airways become compromised, then respiration can become more difficult. Most common among the causes of these types of illnesses is asthma. Also prominent is chronic obstructive pulmonary disease, which is a significant cause of death worldwide. In addition to reviews of diseases affecting the airways, this issue also covers airway anatomy and variants, congenital anomalies of airways, and CT-bronchoscopic correlations.