Over the last five years we have repetitively treated a group of 21 Iranian soldiers who developed pulmonary complications as a result of severe inhalation injury due to mustard gas during the Iran-Iraq war. Early respiratory manifestations included hemorrhagic inflammation of the tracheobronchial tree accompanied by severe erosions. Secondary complications consisted of chronic infections, suppurative bronchitis, and extensive stenotic process of the entire tracheobronchial tree with life-threatening sequelae. After a delay of up to 15 months, scars, ulcers, and strictures developed in the central airways. Progressive deterioration of gas exchange was common. At this point, bronchoscopy, both diagnostic and therapeutic, was invaluable in evaluating the conditions in these patients since many required multiple therapeutic bronchoscopies. Repeated bougienage of the stenotic tracheobronchial lesions and laser photoresection of scarring tissue was life-saving. The recurrence rate of stenosis was very high, with intervals of less than six months on the average. One pneumonectomy was necessary, with the excised lung showing bronchiectasis and chronic pneumonia. To this date we have performed 146 therapeutic bronchoscopies. In four patients, silicone stents had to be implanted. One patient received brachytherapy and external beam radiation therapy in an effort to prevent continued scarring and life-threatening stenoses of the tracheobronchial tree. Our experience demonstrates the extreme usefulness of bronchoscopy in the diagnosis and treatment of pulmonary complications due to inhalation of poisonous gases.