Enterococcus faecalis is the most commonly isolated or detected species from oral infections including marginal periodontitis, infected root canal and periradicular diseases. So, the elimination of bacteria, their products and substrate enhances the success rate of endodontic therapy. Thus, this study was done to compare the antimicrobial efficacy of two different root canal techniques using K-file and K-Nitiflex. 30 intact right and left maxillary premolars extracted for orthodontic reasons were included in this study, after pulp extirpation, teeth were decoronated and autoclaved. Root canals were inoculated with Enterococcus faecalis suspension incubated at 37__ampersandsigndeg; for 24 hours. Six teeth were randomly allocated to five groups such as Step back preparation using K-file, Step back preparation using K-Nitiflex , Standard preparation using K-file, Standard preparation using K-Nitiflex and Saline irrigation. A pretreatment and Post- treatment sample was obtained and its prevalence was evaluated using cultivation. All the data were statistically evaluated. The results suggest that the reduction in bacterial counts were statistically significant with step back using K-file and K-Nitiflex file and also standard technique using K-file and K-Nitiflex file. Finally, the present study concludes, that mechanical effects along with the adjunctive chemical substances possessing antimicrobial properties would effectively eradicate root canal infections.