Air pollution is a complex problem. Different pollutants interact in the atmosphere, affecting our health, environment and climate. Air pollutants are emitted from almost all economic and societal activities. Emissions of many air pollutants have decreased across Europe in recent decades, resulting in improved air quality. However, the concentrations of some polluants are strongly influenced by the intercontinental transport of these substances. This study highlights the role played by climatic conditions specific in several regions of Romania. In this sense, a comparative analysis of the air quality determined for the cities of Galati, Constanta and Brasov (Romania) is presented. These cities have about the same population, comparable industrial development, but are subjected to different geo-climatic conditions.