Background: Red rose flower (Rosa damascene Mill) is a plant that contains antibacterial. Red rose flower has active substances such as flavonoids, tannins, geraniols, nerols, and citronellols which have been shown to inhibit the growth of gram-positive and gram-negative bacteria. Streptococcus mutans is a grampositive bacteria that found in pulp necrosis teeth. Objective: To determine the antibacterial effect between red rose flower extract (Rosa damascene mill) and chlorhexidine digluconate 2% against Streptococcus mutans bacteria as root canal irrigation material. Design: Experimental laboratory in vitro. Red rose flower extract (Rosa damascene Mill) was made using the maceration method with ethanol 70%. There were six groups tested, four concentrations of red rose flower extract (100%, 75%, 50% and 25%), positive control (chlorhexidine digluconate 2%) and negative control (sterile distilled water). The test bacteria used were Streptococcus mutans. The calculation of antibacterial effect by measuring radical zones. Result: Chlorhexidine digluconate 2% has the highest antibacterial effect compared to the red rose flower extract (Rosa damascene Mill) with concentrations of 25%, 50%, 75%, and 100%. At concentration 100% of the red rose flower extract (Rosa damascene Mill) has the highest inhibition compared to other concentrations. Conclusion: Red rose flower extract (Rosa damascene Mill) has antibacterial effect against Streptococcus mutans bacteria.