Abstract Introduction: Lactobacillus acidophilus is one of the bacteria causes dental caries. The previous study has shown that Kaempferia galanga extract has a potential to inhibit the growth of Lactobacillus acidophilus. Objective: To determine the antibacterial effect of Kaempferia galanga extract to Lactobacillus acidophilus. Methods:Kaempferia galanga is extracted in 3 different sol…