The authors describe the use of the fiber bronchoscopic method in the respiratory distress syndrome of adults (RDSA). The method permits visual assessment of bronchial status and allows obtaining cell elements and mediators which are regarded not merely as a result of bronchoalveolar involvement, but as markers of the degree of this involvement. Special attention is paid to cellular and chemical components of bronchial secretion and to detection of correlation with the identical values of arterial and venous blood. The authors classify the available data on bronchological methods of examination, define their role in the diagnosis and treatment of RDSA, and analyze correlation between these data and clinical stages in the course of the syndrome.