Over the past few years, research on the quality of air and microorganisms present in the atmosphere and spore composition of the environment has increased significantly, due to concerns over health risks for humans, plants, and animals. This study shows the abundance and diversity of microorganisms and the atmosphere of an urban nucleus, that is, the city of Valladolid (Spain). We considered the conditions of precipitation, humidity and wind, and the presence of some atmospheric pollutants such as nitrogen dioxide and nitrogen monoxide (NO 2 /NO), carbon monoxide (CO), sulfur dioxide, and particulate matter (PM10 and PM2.5). After their deposition present at five geographic points with different environmental conditions, differences were observed in the proportion of bacteria growth which was characterized by growth in several specific culture media. Most identified the Gram-negative bacteria identified in the air samples collected belong to the genera Staphylococcus and Streptococcus. Gram-positive bacteria were present at a low rate.