A 52-year-old man was admitted to our department because of hypercapnic respiratory failure. His illness had begun with scleritis 5 years before, followed by swelling of the fingers and auricular cartilages and saddle nose 3 years before, when a clinical diagnosis of relapsing polychondritis was made. His chest CT after intubation revealed diffuse airway narrowing with complete collapse of both main bronchi on expiration. Though his clinical status was stabilized after initiation of mechanical ventilation and pulse-dose corticosteroid treatment, he was difficult to wean from the ventilator with a conventional on-off trial. We therefore assessed the diameters of the central airways using dynamic CT under application of bilevel PAP, which confirmed an improvement in airway patency. He was then successfully weaned from artificial ventilation using bilevel PAP, initially through tracheotomy and subsequently via a nasal mask. To our knowledge, this is the first report that confirms the advantage of bilevel PAP objectively for a patient with labile airways.