This study aim to evaluate antimicrobial efficacy of sodium hypochlorite (NaOCl) and ozonated water against Enterococci faecalis biofilm. The bacterial biofilm was exposed to 2.62%, 1.31% NaOCl and 0.1 ppm ozonated water over a range of time periods. The presence of viable cells was determined by enumeration of colony forming units (CFU). All experiments were repeated four times (n=4). The effectiveness of the agents was compared using nonparametric Kruskal- Wallis test. The result revealed that 2.62% of NaOCl can completely kill E. faecalis biofilm in 15 minutes whereas 1.31 % NaOCl required a longer time to produce such effect. 0.1 ppm ozonated, however, did not exhibit any antimicrobial effect within the period of time tested. From this study, it can be concluded that 0.1 ppm ozonated water was not comparable with 2.62% and 1.31% NaOCl in antimicrobial efficacy against E. faecalis biofilm.