Aim: The aim of this systematic review was to investigate the in vitroantibacterial effect of sodium hypochlorite gel on enterococcus faecalisduring root canal treatment.Methodology: An electronic databases (PubMed, ScienceDirect, GoogleScholar, CENTRAL, Health Advance) was performed (last updated was 1stApril 2019). The reference lists of the included studies were handsearched. Randomized in vitro studies that compared sodiumhypochlorite gel to solution as a root canal irrigant were included. Nolimitation on publications date.Results: Out of 20741 articles, only two studies with 116 human teethwere included in this review. The studies showed 50% high risk of bias,and 50% medium risk of bias for the included studies. Both sodiumhypochlorite gel and solution had some bacterial growth inhibition overE-faecalis. The heterogeneity in methodology of the included studies andthe lack of high evidence led to contradictory results. However, sodiumhypochlorite solution was better in enhancing the antibacterial effectaccording to the robust study.Conclusions: There is insufficient reliable evidence about theantibacterial effect of sodium hypochlorite gel on enterococcus faecalis.Although the robust study included in this review revealed that sodiumhypochlorite gel is less efficient than the solution as a root canal irrigant,further studies are needed to consider the most effective type,concentration, duration and treatment protocols in enhancing theantibacterial effect of sodium hypochlorite.