Objective: Three different pulp capping compounds, Dycal, Rootdent MTA, and Biodentine, were assessed for their antibacterial effectiveness against Streptococcus mutans and Enterococcus facials microorganisms and were investigated by agar diffusion test. Materials and methods: A total of (10) sterilized Petri plates of agar were arbitrarily assigned into 2 groups conferring on the type of tested microorganisms applied (n=5); A1 and A2 for Streptococcus mutans and Enterococcus facials, respectively. In each group, the experimented materials were classified into three major groups: I, II, and III corresponding to Dycal, Rootdent MTA, and Biodentine. Every major group was divided into three distinct subgroups based on the observation periods: (TB1), (TB2), and (TB3) observed after 1, 2, and 7 days, respectively, in order to examine the presence of growth inhibition zones (GIZs) that developed around pulp capping materials. Using a digital micrometer, the size of bacterial growth inhibitory zones was measured to the closest hundredth of a millimeter. Results: All tested materials exhibited antibacterial activity against both tested microorganisms. In Streptococcus mutans, in (TB1), the greatest diameter of bacterial GIZs was performed around Biodentine, followed by Rootdent MTA and Dycal, respectively. In Enterococcus facials, the greatest diameter of bacterial GIZs was formed around Rootdent MTA at all evaluation periods, followed by Biodentine and Dycal, respectively. Conclusions: All the tested bioactive materials effectively inhibit the growth of both microorganisms. Rootdent MTA was more effective against Enterococcus facials, Biodentine was more effective against Streptococcus mutans, while Dycal was the least effective material against both microorganisms.