The process of urbanization in this new millennium is characterized by the fact that more than three quarters of Europe's population is concentrated in urban areas, thus it becomes essential the issue of how to reconcile the development of our cities with the respect and protection of the environment. Polluting vehicle emissions constitute a major contribution to the deterioration of urban air quality and represent a potential risk to public health of citizens. The qualitative improvement of processes of production it is to be considered in the near future, a priority for urban pollution reduction and for improving the quality of life of our cities. This paper shows the air pollution analysis of the urban center of four Sicilian city, and the concentrations of the critical pollutants (PM10∗NO2∗SO∗O3∗CO∗C6H6∗NH3∗COVNM.). Linear regressions were performed to represent the relationships between the main pollutants; they were analyzed also the differences between the concentrations of pollutants, and their progress over the years.