Objective: The purpose of this study was to evaluation and comparing the compressive strength and antimicrobial effect of mineral trioxide aggregate (MTA) and a newly developed endodontic material (DiaRoot). Materials and methods: in this study a total number of samples of 75 was used (n=75). They were divided into two major groups. Group A (MTA samples)and group B, each of 74 samples each. Group A was further subdivided in to sub group 1 measuring compressive strength (n=20), sub group 2 measuring anti-bacterial test (n=54). Group B was divided the same way Group A was divided. The samples in subgroup 1 were measured after 3 days (n=10) and 21 days (n=10). For subgroup 2 E. feacalis (n=27) and S. aures (n=27) were measured. Results : The Student t-test analysis showed a significant difference in compressive strength mean values between DiaRoot and MTA at P <0.05. There was no statistically significant difference between 3 days-old mix and 7 days-old mix which showed the statistically significantly lowest means optical densities. Conclusion: It was found that time has an influence on compressive strength. There was similarity between MTA and DiaRoot as regards their antibacterial activity against the two species. The direct contact test seemed to be efficient in determining the antibacterial activity of the material.