The purpose of the present study was to evaluate the efficacy of chlorhexidine ultrasonic and photodynamic therapy against E.faecalis. Sixty teeth were used in this study. The crowns were decapitated and the root canals were biomechanically prepared using step-back technique. Sixty teeth were divided into three main experimental groups, twenty three teeth each, according to the method of intra canal treatment. Group I: 2% chlorhexidine medication. Group II: combined medication (U.S + CHX). Group III: photodynamic therapy (Asptim). Antibacterial efficacy was assessed before and after treatment. These samples were cultured on KF streptococcus agar media, incubated for two days then colony forming units were counted. Under the experimental conditions tested, the antibacterial efficacy of photodynamic therapy against E.faecalis provided a better effect than chlorhexidine or ultrasonic + chlorhexidine. However there was no statistically significant difference among the different groups.All the tested materials were effective. 1] Combination of ultrasonic plus 2% chlorhexidine solution seems to be the best effective treatment against E.faecalis by 99.71%.2] The photodynamic therapy (low power diode laser) with output power 100mw for 2 minutes possess an excellent antibacterial efficacy by 99.69%. 3] 2% Chlorhexidine solution seems to be a promising treatment against E. faecalis by 99.69%.