Lichens have been widely used in biomonitoring studies. In this study, Cd, Cu, Pb and Zn concentrations in some foliose and fruticose lichens which arc found in Samsun were investigated and the differences among the species in terms of trace element concentrations and possible interactions among heavy metals were also examined. The results of the present study show that the study area is polluted by Pb and Cd. The cadmium contamination levels were also higher than those of the other elements. The highest Pb (101.39 ppm), Cu (43 ppm) and Zn (67.60 ppm) levels were found in Physcia adscendes. In addition to this, Hypogymnia physodes is one of the foliose species and the best accumulator of Cd (245.73 ppm) as compared to the other species.