Bacterial flora of various strains was isolated from sputum and in some cases from BAL fluid of 75 patients with obstructive pulmonary disease experiencing dyspnea symptoms accompanying infections of respiratory tract. Among strains recognized traditionally as pathogenic in respiratory tract, we also isolated various strains typically called "normal oropharyngeal flora", "physiologic" or "non-pathogenic" bacteria. Those latter strains used in the skin tests in autologous manner for each patient had the property of provoking early (15 min) and late (24-48h) reactions. Early reactivity resembles that induced in the tests with airborn allergens. This suggests a potentially important role of those currently ignored strains in pathogenesis of obstructive pulmonary disease.