São Paulo metropolitan area presents an intense and chaotic process of urbanization and industrialization. Due to this processes, this region has big atmospheric pollution problem. In certain months of the year, this problem gets worse due to the unfavorable dispersion conditions. The pollutants cause undesirable effects to the environment and to the human health. The chemical characterization and the mutagenic activity evaluation of the compounds present on the atmospheric particulate matter (APM) represents an analytical challenge and it is very important for understanding of the correlation among pollutants, health hazards and emission sources.The goal of this work was chemically characterize the polar and moderately polar organic extracts from the APM collected in São Paulo city and to evaluate their mutagenic activity.The APM is a complex mixture of organic and inorganic compounds present in large range of concentration. Due to this complexity, the chemical fractionation of these organic extracts is necessary to isolate classes or individual compounds, to allow their identification and quantification.The results obtained using different analytical techniques demonstrated that the dichlorometane and acetone extracts has several organic compounds belonging to differerit classes, such as, polycyclic aromatic hydrocarbons, quinolines, ketones, pyridines, furanes, aldehydes, amides and amines. Some of these compounds are considered carcinogens and/or mutagens. The dichloromethane extract presented the highest mass yield and its composition is almost exclusively organic. The acetone extract has organic and inorganic species.Mutagenicity tests revealed that the APM from São Paulo city presented a have relatively high mutagenic activity when compared to other urban regions.