The present study was conducted out to determine hyperforin, hypericin, pseudohypericin, chlorogenic acid, rutin, hyperoside, quercitrin, quercetin, kaempferol, apigenin-7-O-glucoside and amentoflavone contents of Hypericum adenotrichum, an endemic plant species to Turkey. The aerial parts representing a total of 30 individuals were collected at full flowering, dried at room temperature and assayed for secondary metabolite concentrations by HPLC. All of the chemicals were detected at various levels except for hyperforin. This is the first report on polar chemistry of this endemic species.