Abstract Origanum bargyli Mouterde is a rare plant of this genus in Turkey. Essential oils from the aerial parts of O. bargyli were obtained by hydrodistillation. The chemical composition of the oils was analyzed by GC/MS. From the 24 identified constituents, p-cymene (19.6%), borneol (12.9%) and Î±-terpineol (11.0%) were found to be major components. Furthermore, the oil was tested against 11 bacteria and four fungi at different concentrations. The result showed that the oil exhibited significant antimicrobial activity.