The performance of two epiphytic lichen species (Evernia prunastri (L.) Ach. and Parmelia sulcata Taylor) as bioindicators of heavy metal pollution in natural areas around the city of Nis (southeastern Serbia) were evaluated. The concentration of 19 heavy metals in lichen samples was measured by inductively coupled plasma-optical emission spectroscopy. For the majority of the elements the concentrations found in Parmelia sulcata Taylor were higher than in Evernia prunastri (L.) Ach. In addition, interspecific differences in heavy metal accumulation between Evernia prunastri (L.) Ach. and Parmelia sulcata Taylor are observed. Parmelia sulcata Taylor showed a tendency to accumulate Fe, Mn, Ni and Ti while Evernia prunastri (L.) Ach. preferentially concentrated Cu on both locations. A clear distinction between lithogenic (Mn-Cu-Ti) and atmospheric elements (Ni-Co-Cr-Ag-Pb-Hg) was achieved by cluster analysis.