Relatively few reports exist regarding isolated smoke inhalation injuries in human patients. In this study, we describe the acute manifestations and short-term evolution of respiratory injuries after isolated smoke inhalation in victims of fires. Ninety-six patients admitted as the result of a subway fire were examined for acute respiratory dysfunction with clinical outcomes. Some of the survivors suffering from less severe injuries were evaluated for changes in pulmonary function over time, with the effects of steroid treatment. In 13 patients (14%), immediate respiratory failure resulted from ventilatory insufficiency, which was induced principally by mechanical airway obstruction, and manifested as significantly lowered pH and higher PaCO2 levels than in the patients requiring no mechanical ventilation. Toilet bronchoscopy allowed for early liberation from mechanical ventilation. Along with the death of 4 patients (4%), vocal cord and tracheal stenosis were noted in 5 patients and 1 patient, respectively, among 17 patients for whom endotracheal intubation was required. Pulmonary functions improved significantly after 3 months, with no further changes being observed within the subsequent 3 months. Steroid therapy resulted in no additional improvements in the pulmonary functions of these patients. In patients with isolated smoke inhalation injuries, immediate ventilatory insufficiency resulting from mechanical airway obstruction should be watched for, and managed via toilet bronchoscopy. Vigilance is required to avoid airway complications after endotracheal intubation. The improvement of pulmonary functions progressed primarily within the first 3 months, whereas short-course steroid therapy exerted no influence on the eventual recovery of pulmonary functions in the less severe cases.