The use of fixed orthodontic appliances in the mouth becomes one of the factors of plaque retention that can cause gingivitis. Starfruit leaf extract (Averrhoa bilimbi L) is one of herbal antibacterial ingredients that are believed to inhibit the growth of bacteria that cause gingivitis. Antibacterial power is obtained from the leaves of starfruit active substance including flavonoids, tannins and saponins. The purpose of this study is to test the inhibition extracts of leaf starfruit (Averrhoa bilimbi L) against the bacteria that cause gingivitis in patient with fixed orthodontic appliance.. The research design in this study were pure laboratory experimental in vitro by using a diffusion method. Gram positif anaerobic bacteria obtained from the swab in the gingival sulcus fluid using paper points in patients with fixed orthodontic appliance The treatment group was divided into 6 groups: leaf extract starfruit in consentration 12.5%, 25%, 50%, 100% t, sterile aquades (control negative), chlorhexidine 0,2% (control positive) and repeated 5 times. Research used the media petri dish studies with pitting and incubation 37°C for 24 hours. Clear zone will be seen around the wells was then measured using a caliper to millimeters. Data were analyzed using One Way ANOVA followed by a Post hoc LSD test. The result from this study is indicate that extracts of leaves starfruit can significantly inhibit the growth of bacteria that cause gingivitis (p <0.05).