Air pollution results in smog, acid rain, ozone hole, global warming, as well as cardiovascular and respiratory diseases. It also contributes to cancer, which increasingly often occurs in children. Children and infants are particularly vulnerable to air pollution because their immune, respiratory and central nervous systems are not fully developed. Compared to adults, children often spend more time outdoors, and due to their lower lung capacity, they also breathe more frequently, which means that they inhale much more air than adults, in relation to their body weight. The article concerns the data on the meteorological conditions, air quality (annual average concentration of nitric oxides, benzo(a) pyrene, PM2.5 and PM10 particulate matter) as well as morbidity and hospitalization due to the respiratory, circulation and cancer diseases in Bielsko-Biala in 2010–2018. The hypertension, cardiovascular malformations and cancer incidence among children and adolescents, has been systematically increasing since 2010, just like in the case of hospitalization due to bronchial asthma and congenital malformations. The basic cause of poor air quality in Bielsko-Biala is low emission and inversion phenomenon which are perfect conditions for smog development. Therefore, certain actions must be taken, which can include: liquidation of coal boilers and their replacement with environmentally friendly energy sources (e.g. subsidy of 100% return on investment costs), introducing communication solutions that will lead to a reduction in linear emissions, free communication and ecological education.