Aim: The aim of this study was to evaluate the antibacterial effect of Methanolic Extract of Salvadora persica against Enterococcus faecalis biofilm as an endodontic irrigant. Methods: 64 recently extracted permanent human mandibular premolars were used in the study. Teeth were decoronated at the cervical area by means of high speed diamond tapering stones under water cooling. All teeth were prepared using the ProTaper Next system utilizing the crown down technique till size X4 then specimens were divided into 4 groups as follows, Group 1: 16 samples were irrigated with 5 ml Salvadora Persica 5 mg / ml, Group 2: 16 samples were irrigated with 5 ml NaOCl 2.6%, Group 3: 16 samples were irrigated with BioPure MTAD, Group 4: 16 samples were irrigated with 5 ml Chlorohexidine 2%. The root canals were dried and refilled with sterile distilled water. Then a sterile paper point size 40 was inserted into each canal and maintained for 3 min for sample collection. For each group, a classical bacterial counting method was employed to recover viable E. faecalis on Mueller-Hinton agar plates. Afterwards, the mean CFU value for each group's plates was calculated. Statistical analysis was done by one way ANOVA followed by pair-wise Tukey’s post-hoc tests to detect significance between subgroups. The significance level was set at P ≤ 0.05. Results: Irrigation with S. Persica, NaOCl 2.6%, MTAD and Chlorohexidine 2% resulted in percentage reduction of the mean and standard deviation values of bacterial count equal to 95.07±1.76, 96.04±0.90, 97.89±0.50 and 88.67±0.50 respectively. The results of the ANOVA test showed that there was a statistically significant (p<0.05) difference between all groups. Pair-wise Tukey’s post-hoc test showed non-significant (p>0.05) difference between NaOCl 2.6% and MTAD. Conclusions: The results of this study demonstrated the effectiveness of S. persica methanolic extract against E. Faecalis biofilm and could be used as a powerful endodontic irrigant