Air pollution remains a critical environmental issue with detrimental impact on living organisms and ecosystems’ health. This study evaluates air pollution in Jaipur City using lichen transplantation techniques to examine physiological effects on Pyxine cocoes (Sw.) Nyl. The lichen specimens were collected from Nahargarh Wildlife Sanctuary and transplanted to eleven urban locations for 90-day exposure periods. We measured concentrations of six potentially toxic elements (cadmium, chromium, copper, lead, nickel, and zinc), photosynthetic pigments (chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids), chlorophyll degradation, chlorophyll stability index, and vehicular frequency. Results revealed significantly higher concentrations of all six potentially toxic elements in transplanted lichens compared to control, with decreasing order of abundance: Zn > Pb > Cr > Ni > Cu > Cd. This study validates P. cocoes as a reliable and cost-effective biomonitoring tool for urban air quality assessment, providing essential baseline data for environmental management and policy development in rapidly urbanizing cities of developing countries. Keywords Air pollution · Biomonitoring · PTEs · Pyxine cocoes · Urban environment · India.