The chapter presents the results of pulmonary function tests conducted as part of the Polish Spirometry Day of 2011, an initiative aimed at increasing the awareness of causes, symptoms, and delayed effects of common respiratory diseases, in particular of bronchial asthma and chronic obstructive pulmonary disease, and at demonstrating the role of regular examinations, especially in higher risk groups. The results show that there was a relatively substantial group of persons, 11.2 % of the population sample studied, not being aware of a respiratory disease they had. Furthermore, the results show that quite often, 12.4-16.0 % of the population studied, obstruction was diagnosed in persons who did not have any spirometry tests done before, despite some respiratory symptoms that should raise the attention of general practitioners to perform such tests.