Atmospheric air contamination by pesticides present in particulate matter is considered ubiquitous and can be found in different regions of the world. Atmospheric particulate matter can be collected by separating the fine from the coarse particles, simulating the action in the respiratory tract. The presence of pesticides in particulate matter fractionated by size was investigated in a peri-urban region, where agriculture is intense. Weekly samples were obtained using a cascade impactor. The gravimetric determination was obtained using an ultra-analytical balance. Identification and quantification of pesticides were obtained using UHPLC-MS/MS for 105 pesticides. The average concentration of total PM of 25.2 µg m-3 and maximum concentration of 44.2 µg m-3 were obtained. Azoxystrobin, carbendazim, chlorimuron, difenoconazole, diflubenzuron, ethephon, metolachlor, pyraclostrobin and trifloxystrobin were determined in the inhalable fraction (2.5 to 10.0 µm). In the fine fraction (1.0 to 2.5 µm) carbendazim, ethephon, metolachlor and trifloxystrobin were determined and in the 0.5 to 1.0 µm fraction, clomazone, ethoprophos, fenpropimorph, metalaxyl, pyrimethanil and propoxur were determined. Cyproconazole and metolachlor were determined in the <0.25 µm range and acephate was found in the coarse and fine ranges. The population in the region is exposed to possible risks when breathing particulate matter containing pesticides. These studies are essential to support public policies and more sustainable agricultural practices, promoting food security and environmental protection.