Thermal injury is diagnosed by fibrobronchoscopy within the first 5 days after inhalation burn trauma in 73 patients (34% of the total number of patients hospitalized during the last 2 years). Pathological changes of the mucosa with predominant lnultiple ulceration at different levels of the tracheobronchial tree are detected in 44% patients and in more than 70% patients with acute respiratory deficiency. These changes determine variation and severity of thermal inhalation injury in the patients, and, together with morphofunctional characteristics, provide objective basis for the early diagnostics and prognosis.