Abstract The Serbian Hypericum perforatum local population D4 was investigated under the different ecological conditions in two districts of Serbia and Greece. The biomass yields resulted in an average of 1937â2021 (kg/ha). The GC and GC-MS analysis of the hydro distilled essential oils showed significant differences in their composition indicating the great influence of the local agro-ecological conditions. Aliphatic compounds (43.83 %) and sesquiterpenes (39.73 %) were the predominant components in the oil from Serbia, while monoterpenes (Î±- and Î²-pinene) were the main compounds in the oil from Greek cultivation.