Aim: to evaluate the antibacterial activity of 5 root canal sealers against E. faecalis in presence or absence of smear layer.Methodology: One hundred (100) specimens were used in the study. They were divided into two main experimental groups, 50 specimens each, according to the type of irrigation, Smear Clear and distilled water. After mechanical preparation all samples were sterilized by autoclaving for 20 minutes at 121°. Each experimental group was subgrouped into five subgroups, 5 samples each, according to the type of sealer used (U/P root canal sealer, AH Plus, Real Seal SE, CRCS, MTA Fillapex). All samples were obturated with lateral condensation technique and inserted inside the incubator at 37°c until time of evaluation. The presence or absence of bacteria was evaluated, both by bacterial counting and scanning electron microscope. Results: results showed that no statistically significant difference was found between each of U/P Root canal, AH Plus, CRCS and MTA. While, a statistically significant difference was found between each of U/P Root canal, AH Plus, CRCS and MTA on one hand and Real Seal SE on the other hand.Conclusion: it was concluded that the highest bacterial count was found in Real Seal SE sealer groups while the lowest bacterial count was found in AH Plus sealer groups.