Introduction: One of the principles of endodontic treatment is to eliminate the microorganism populations in infect-ed root canals. Disinfection is dominant factor in determining the success of treatment because the persistent infec-tion in the root canal leads to endodontic treatment failure. Enterococcus faecalis is one of the bacteria commonly found in root canals after performing endodontic treatment. The peel of yellow Kepok banana (Musa paradisiaca L.) seems to hold many antibacterial properties such as flavonoids, alkaloids, saponins, tannins, and terpenoids. This study aims to determine the antibacterial power of Kepok banana (Musa paradisiaca L.) peel extract against Entero-coccus faecalis bacteria. Methods: This study utilized a tube dilution method to determine the Minimum Inhibitory Concentration (MIC) and employed the striking method on the media to determine the Minimum Bactericidal Con-centration (MBC). The extract concentrations used in the study were 50%, 60%, 70%, 80%, and 90%. The results of the MBC were for observations using a Scanning Electron Microscope (SEM). Results: Yellow Kepok banana peel extract had MIC against Enterococcus faecalis at a concentration of 50%, and had an MBC at a concentration of 60%. In the SEM observation, it was revealed that there were significant differences in the size and morphology of Enterococcus faecalis bacteria in the form of additional cell lengths; additionally, there were blebs on the cell walls of Enterococcus faecalis bacteria. Conclusion: Yellow Kepok banana (Musa paradisiaca L.) peel extract has an anti-bacterial activity against Enterococcus faecalis.