The study was carried out with an aim to assess the heavy metal (HM) and polycyclic aromatic hydrocarbons (PAHs) in the air of a biodiversity as well as tourist-rich area of Western Ghats by applying a most frequent growing lichen Remototrachyna awasthii (Hale and Patw.) Divakar and A. Crespo, as biomonitor. Thalli of R. awasthii were collected from eight sites of Mahabaleshwar area located in Western Ghats. Samples were prepared for HM and PAHs quantification by ICP-MS and HPLC, respectively. Total metal concentration (HM) ranged from 644 to 2,277.5 μg g−1 while PAHs concentration between 0.193 and 54.78 μg g−1. HM and PAHs concentrations were the highest at Bus Stand while control site (Lingmala Fall) exhibited the lowest concentration of HM as well as PAHs followed by samples from Wilson point (both these sites are having trekking route). It was also evident from this study that vehicular emission played a significant role in the release of HM and PAHs as pollutants in the environment. The effectiveness of R. awasthii as biomonitor could be further investigated by comparing this species with other biomonitors.