Purpose: This study aimed to evaluate the antibacterial effect of Green tea as a root canal irrigant using Endovac irrigation System. Materials and Methods: for this study, 60 extracted human teeth were used. After their decapitation, they were instrumented using Universal ProTaper rotary files up to size F4 then separated into 2 set of groups according to the solution used in irrigation; Group A1: irrigated with 5.25% NaOCl Group A2: irrigated with Green tea (30 specimens in each group). We then subdivided each group into 2 subgroups according to the technique used for irrigation; Subgroup A: using conventional irrigation and Subgroup B: using Endovac irrigation system. Samples were sterilized and inoculated with Enterococcus faecalis(ATCC29212) for 48 hrs. After irrigation, microbial samples were collected, transferred to nutrient agar and incubated for counting of bacterial colony forming units (CFUs). The significance level was P≤ 0.05. Results: There was a statistically significant difference among the tested groups and subgroups in the mean scores of bacterial counts. Concerning the irrigating devices, there was statistically significant difference between conventional irrigation and Endovac system as Endovac showed higher antibacterial effect than conventional irrigation (P ≤ 0.05). Green tea showed statistical significant difference with Endovac system subgroup than conventional irrigation (P ≤ 0.05). Conclusion Endovac irrigation system was effective in eradication of E. faecalis from the root canals using either NaOCl or
Green tea.