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 -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.