Air is among the vital human needs to survive. It is the one thing humans cannot be without for longer than a few minutes. Indoor Air Quality (IAQ) is a public and occupational health concern since we are exposed to air pollutants daily, given that we spend almost 90% of our time in indoor environments. IAQ can be affected by numerous factors, from outdoor pollutants that get indoors through ventilation to building materials, furnishing, and activities carried by the building occupants. Exposure to air pollutants has been linked to a panoply of adverse effects on our health, well-being, and performance. The aim of this study was to assess the IAQ in grocery stores (GS) in the municipality of Cascais in the Lisbon district of Portugal, and, consequently, to characterize the workers' occupational exposure to air pollutants. The study was conducted in 13 small “family” grocery stores. The IAQ monitoring campaign was conducted using low-cost technologies and focused on several parameters, namely: Carbon dioxide (CO2), Volatile organic compound (VOCs), Particulate matter (PM10 and PM2.5), Temperature (T), and Relative Humidity (RH). The results were analyzed using SPSS software. Overall, the IAQ of the studied GSs complied with the Portuguese legislation, except for PM2.5, where 23% of GSs presented levels above the established limit value of 25 μg.m-3. The IAQ assessment allowed us to identify the best strategies to improve the workers’ experience in indoor environments at their workplaces.