The accumulation of trace elements in the thalli of epiphytic lichens can reveal levels of trace elements in the ambient air. This study assessed the trace elements in lichen species Pyxine cocoes found in the urban and periurban areas of Kolkata. Trace elemental analysis was carried out using energy-dispersive X-ray fuorescence and protoninduced X-ray emission spectroscopy. Variable levels of elements like Mn, Fe, Cu, Zn, Cr, V and Pb, are detected in the thalli of P. cocoes collected from repressentative locations. Localization of trace elements in the thalli was confrmed by analysis using scanning electron microscope attached with EDX spectrometer. Several pollution indices such as enrichment factor, contamination factor (Cf) and pollution load index were estimated to evaluate the trace element contamination level of the ambient air at the sampling spots. PLI and Cf and values suggest deterioration or air quality that varies from moderate to high level of contamination. Ca, S, Pb, Sr and Cr, are highly enriched at urban sampling spots (1–9). High coefcient of variation values for Ca, S, Pb, Sr and Cr confrm their accumulation from local anthropogenic sources in the urban sampling spots (1–9). However, results of principal component analysis analysis have shown that sources of trace elements in the samples from urban areas include both vehicular emissions and anthropogenic activities. Higher concentration of trace elements in the lichen thalli collected from peri-urban locations is attributed to vehicular emissions from the highways and expressways running through these areas. Keywords: Biomonitor · Epiphytic · Lichen · Trace element · Air pollution · Environment.