Dental caries and root canal infections are common dental and oral diseases due to the dominance of S.mutans and E.faecalis. Despite not having any economic value and becoming a waste, durian peel is claimed as an antibacterial. This study aims to analyze durian peel ethanol extract antibacterial activity against S.mutans and E.faecalis based on the inhibition zone diameter, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). This type of research is a laboratory experiment using Post-test Only Control Group Design. There were 7 concentrations of durian peel ethanol extract (50%, 25%, 12.5%, 6.25%, 3.125%, 1.56%, and 0.78%), both positive and negative control with three times repetitions. Moreover, the bacterial suspensions used were S.mutans ATCC 25175 and E.faecalis ATCC 29212. Data analysis used One Way Anova, while data that were not normally distributed used Kruskal-Wallis. Post Hoc analysis used LSD for normal data and Mann-Whitney for abnormal data. Durian peel ethanol extract shows the antibacterial activity of S.mutans with MIC at a concentration of 0.78%, while against E.faecalis is 12.5%. The higher the concentration, the larger the inhibition zone formed. The best-tested concentration of ethanol extract from durian peel is 6.25-50% to inhibit the growth of S. mutans and 50% for E.faecalis. Durian peel ethanol extract can prevent dental caries since it is antibacterial against S.mutans and E.faecalis.