Tracheobronchomegaly (TBM) occasionally may progress to extensive tracheomalacia which leads to respiratory failure. Spirometry, dynamic expiratory multidetector computed tomography (CT), bronchoscopy are used to diagnose patients of suspected tracheobronchomalacia. We used the technique of night-time monitoring of respiratory variables to show the presence of respiratory abnormalities during sleep and which was corrected by applying nasal continuous positive airway pressure (CPAP). The study showed the presence of both apnoea and hypopnoeas, which were obstructive in nature with an apnoea-hypopnoea index (AHI) of 11, no snoring and associated oxygen desaturation of 75 per cent. A second overnight study with nasal continuous positive airway pressure at a critical pressure of 8 cm, the AHI decreased to 3 along with no drop in oxygen saturation. This non-invasive technique should be considered as a diagnostic tool in tracheobronchomalacia and to know the outcome of CPAP, surgical or stent therapy in this condition.