ABSTRACT Background: Guava or Psidium Guajava L is rich of fibers and minerals that are good for health. The benefit of white guava and red guava leaves almost the same. White guava meat contains tannin that functions to smooth the digestive system, blood circulation, and useful to attack bacteria [1]. Most bacteria can causes various diseases or infection by invading and proliferating in body tissues or oral cavity. One of the bacteria that causes infections such as Staphylococcus aureus [2] Objective: To determine the inhibition of guava leaf extract (Psidium Guajava Linn) against Staphylococcus aureus. Method: This is true experimental posttest only control group design with antibacterial inhibition testing using agar diffusion method by measuring the formed inhibition zone. The concentration of guava leaves extract in the test are 10%, 25%, 50%, and 100% with cefotaxime as positive control and Na-CMC as negative control. Each treatment is replicated four times. Results: The results showed that the extracted of guava leaves (Psidium Guajava Linn) could inhibited the growth of Staphylococcus aureus in concentration of 10%, 25%, 50% and 100%. Results of statistical test by using one-way ANOVA obtained significance value of p