Aim: This in-vitro study aimed to compare the effect of Eighteeth Ulta X Ultrasonic activator device and syringe irrigation using sodium hypochlorite (NaOCl) (5.25%) on reducing Enterococcus faecalis (E. faecalis) count in the root canal space. Materials and Methods: Thirty single rooted mandibular premolars were selected for this study. Root canals were prepared using Edge File-X7 (by EDGE ENDO) and enlarged to size 40/04 taper. After sterilization, all teeth were contaminated using E. faecalis suspension. The teeth were divided into two groups: Group (I) (non-activation group, syringe irrigation technique using 3 mL syringe with 30 gauge needle) and Group (II) (activation group using Ultra X Ultrasonic activator device). Three samples of the Colony Forming Units (CFU) were taken for both groups. First sample before any intervention and named (Group I, Sample 1(GIS1) and Group II, Sample 1 (GIIS1). Second sample after chemo-mechanical preparation and named (Group I, Sample 2 (GIS2) and Group II, Sample 2 (GIIS2). Third sample with no activation of irrigant and named (Group I, Sample 3 (GIS3) and with activation of irrigant and named (Group II, Sample 3 (GIIS3). Data were statistically analyzed using Shapiro-Wilk's test, Levene's test and independent t-test (p<0.05). Results: There was a significant reduction of E. faecalis count at Sample 3 in Group II in comparison to Group I p<0.001). Conclusions: It was concluded that the use of Ultra X Ultrasonic activator device significantly eliminated bacterial count in the root canal space in comparison to non-activation, irrigating syringe technique.