Long segment narrowing of the trachea, proximal bronchi is less common than a short segment stricture – which is most often secondary to prolonged intubation.Long segment narrowing is most often seen after tuberculous involvement of the airways. Other causes are aspergillosis, sarcoidosis, wegener’s granulomatsis, amyloidosis, and rarely relapsing polychondritis, traceobronchopathia osteochondroplastica etc. Short segment stricture may also be a sequelae of viral laryngotracheobronchitis in infancy, or result from bronchial adenoma, carcinoid, congenital bronchial atresia (apicoposterior segment of the left upper lobe is commonest site), squamous cell carcinoma (seen in older men - smokers), adenoid cystic carcinoma (a low grade neoplasm with a propensity for local recurrence and seen in relatively younger age) or any of the above-mentioned causes.There is associated tracheomalacia due to weakening of the cartilage, which leads to a tendency to collapse during expiration- with associated distal air trapping, recurrent infections, bronchiectasis and atelectesis. CT thorax with multiplanar reconstruction is the imaging modality of choice for measurement of the length and luminal size of the stenosed segment for therapeutic planning such as balloon dilatation of the trachea.