Kaffir lime (Citrus hystrix DC.) essential oil (peel, leaves, twigs) contains several secondary metabolic compounds, namely phenol. The content of phenol compounds in kaffir lime essential oil (from peel, leaves, and twigs) is one of the compounds that exhibits antimicrobial activity. The purpose of this study was to determine the characteristics and antimicrobial activity of kaffir lime essential oil (peel, leaves, and twigs) obtained through water steam distillation, against the pathogenic bacteria Escherichia coli, Staphylococcus aureus, and Salmonella sp. The method used in this research was to extract essential oil from a part of the leaves, peel and twigs kaffir lime plant, then analyse the characteristics (moisture content, antimicrobial, antioxidant, total phenolic and vitamin C). The result (sequentially of peel, twigs and leaves) showed moisture content of raw material (64.31, 50.035 and 64.94) %; total phenolic (10.71, 9.42 and 9.72) %; refractive index (1.541, 1,451 and 1,467) nD25o. The colour of the essential oil was yellow. The results of the antimicrobial test on kaffir lime essential oil (peel, leaves, and twigs) showed an effect on pathogenic bacteria, with the highest inhibition zone observed in the leaf essential oil at 27 mm. Staphylococcus aureus showed the highest inhibition zone in leaf essential oil, at 20 mm. Salmonella sp. showed the highest inhibition zone in the peel essential oil, at 13.5 mm. This study concluded that the most effective sample of kaffir lime essential oil (leaves) inhibited Escherichia coli bacteria with the highest inhibition zone of 27 mm. Kaffir lime essential oil can be used in food, cosmetics, and medicine fields because it can kill harmful bacteria
