The patient, a 62-year-old woman, complained chiefly of cough. We planned chemoradiotherapy for squamous nonsmall cell lung cancer. A single dose of 2-Gy irradiation and no anticancer agent administration exacerbated the airway stenosis with severe respiratory failure. Urgent tracheal intubation was performed, and a tracheal stent was implanted under extracorporeal membrane oxygenation (ECMO). Because her performance status (PS) worsened from 1 to 2, we administered radiotherapy. The tumor size decreased. There was no recurrence for the next 3 months, and her PS improved to 1. Emergency tracheal intubation and tracheal stent placement under ECMO can be effective for exacerbated airway obstruction after radiotherapy.