Infection is the most common disease in Indonesia. Infection diseases are caused by microorganisms such as the Staphylococcus aureus. While in fact, many plants can be used as traditional medicine, one of those is the leaves of belimbing wuluh tree (Averrhoa bilimbi L.) This study aims to determine the inhibitory power of leaves of Cucumber tree (Averrhoa bilimbi L.) on growth of Staphylococcus aureus in vitro. This study used an experimental method. The technique used to measure antibiotic activity is the method of disk diffusion and continued by Kruskal-Wallis test and Mann-Whitney test. Leaves of belimbing wuluh tree (Averrhoa bilimbi L.) at concentrations of 40%, 60%, 80%, 100%, amoksisilin, and aquabidest resulted in average diameter of clear zone. leaves of belimbing wuluh tree (Averrhoa bilimbi L.) have an inhibitory power against Staphylococcus aureus.