The aim of this study was to evaluate and compare the antibacterial activity ofsilver nanoparticles irrigating solution with chlorhexidine gluconate and sodiumhypochlorite irrigating solutions. Materials &Methods: Ten petri agar plates weredivided into four main groups, according to the irrigating solutions used 0.04%AgNPs, 2% CHX, 5.25% NaOCl and control group. Each group was furthersubdivided into three subgroups according to the incubation periods, 2 hours, 48 hoursand 7 days. Plates were streaked with the respective stock culture of E. faecalis. Afterincubation, zones of inhibition were measured around the paper disks contained theirrigants. Results: The results of this study indicated that after 7 days incubationperiod, zones of inhibition for 2% CHX were significantly larger than those seenaround the filter papers of AgNPs and undiluted NaOCl (p < 0.001 for both)compared to that of 2 and 48 hours periods. Conclusions: This study revealed thatAgNPs in a remarkably lower concentration would possess the same bactericidaleffect as 5.25% NaOCl.