Microplastic particles with diameters of <5 mm has been a component of the Earth since the 1950s. Today, microplastics are ubiquitous in nearly all ecosystems across the world, from mountains to poles, because of excessive plastic waste mismanagement and loss to the environment. Atmospheric microplastics has attracted scientific attention due to its pervasiveness and persistence, raising concerns about potential public health implications from inhalation. We investigated the abundances and characteristics of atmospheric microplastics in Mexico City, Latin America’s second most densely populated city, during the dry and wet seasons of 2020. The results showed that microplastics were detected in all of the samples examined, with abundances ranging from 0.094 to 0.324 microplastic items m-3. Furthermore, ATR-FTIR spectral analysis identified the microplastics as consisting of cellophane, PE, PET, PA, and regenerated cellulose. Based on our data, we estimated that Mexico City residents inadvertently inhale up to 2.4 ± 0.975 microplastics daily, for a total of 876 ± 355.875 microplastics per year/per capita. This study presents the first evidence of widespread microplastic contamination in airborne particulate matter in Mexico City, where air pollution is a longstanding concern, necessitating more research and close monitoring.