abstract aerial parts of hypericum perforatum l. (hypericaceae) were collected from five wild populations in kosovo, with aim to investigate the chemical composition and natural variation of essential oils between wild populations. this species could be considered of economic potential as it is widespread in kosovo, on the other hand h. perforatum is one of the best-known medicinal herbs used in kosovo folk medicine. essential oils were obtained by steam distillation and analysed by gc-fid and gc-ms. sixty-seven components were identified. the yields of essential oils differed depending on the population and ranged from 0.04 to 0.26% based on dry weight. the aerial parts of h. perforatum were characterized by the following main constituents: 2-methyl-octane (1.1-15.5%), -pinene (3.7-36.5%), -caryophyllene (1.2-12.4%), caryophyllene oxide (3.3-17.7%) and n-tetradecanol (3.6- 10.4%). hierarchical cluster analysis revealed that the concentration of components depends on the origin of the plant populations, thus -pinene and 2-methyl-octane were present in the highest concentration in population originating from gjakove, prizren and ferizaj, whereas in the populations originating from peje and prishtine the most abundant constituents were caryophyllene oxide, -caryophyllene and n-tetradecanol. further investigation is needed to establish the natural variability and chemopolymorphism of this species in the territory of kosovo, which should be supported by molecular level analyses.