abstract leaf essential oil of coleus aromaticus (lamiaceae) from cambodia was steam-distilled and investigated for its percentage composition and antibacterial activity against ffteen oral microflora pathogen strains. the volatile oil sample investigated in this work contained mainly thymol (57.4%), carvacrol (13.5%), -terpinene (5.6%), and p-cymene (5.2%). the in vitro antibacterial experiments revealed that on tested bacteria the minimum inhibitory concentration (mic) ranged 40-80 ul/land the minimum bactericidal concentration (mbc) 80-150 ul/l. these findings support the idea that the c. aromaticus essential oil sample tested here could be suitable for use as a natural active ingredient in natural and low-cost drugs against oral microflora.