A report about examinations of foundries' workers who live in the destrict Schwarzenberg is given. Hereby the prevalence of chronic bronchitis should be analyzed in comparison to nonexposed controls. In result 21.1% among foundries' workers and 10.2% among controls had symptoms of chronic bronchitis. The differences are significant. As expected it could be shown, that smoking habits and age are further factors for development of chronic bronchitis. Both the observance of occupational limit-values for dusts and other harmful materials at the work place, which have effects on the respiration system, and the medical survey of workers with the use of special methods for examination of respiratory system are necessary. In workers with findings of respiratory system the factory doctors and pulmonary physicians have to decide together the ability to work in the foundry.