An alternative route to evaluate air pollution and its impact on the environment is using bioindicators, such as lichens, for example. The main purpose of this paper is to demonstrate that the use of lichens can be a simple and economically feasible way to detect and monitor air pollution. Qualitative and quantitative analyses, such as the survey of the specific richness, coverage and frequency of the lichen flora have been made. They have been calculated based in the Index of Atmospheric Purity (IAP) values obtained through seasonal campaigns carried out from January to October in 2017 at four locations in the Miguel Pereira District – State of Rio de Janeiro. 21 “taxon of lichens” distributed in 09 families and 13 genera have been detected. Locations 3 and 4 (Javary lake and São Roque street) have shown higher values of specific richness and IAP (21.66 and 31.45, respectively) which indicate the air pollution at these locations as being respectively regular and low. On the other hand, at the other two locations (Aurea street and Bus Terminal), the specific richness and IAP values found – 7.91 and 11.23 indicate high and high air pollution, respectively. These values and associated indicators lead to believe that the more urbanized an area is, the higher is its air pollution.