Background and Objectives: MTA is the material of choice for Pulp capping, Apexogenesis, Apexification, Perforation repair and as well as for Root end filling. In this in vitro study, different mixing reagents were tested and their effect on the compressive strength, at different pH, was evaluated when MTA was mixed, individually with each of them. Materials and Method: A total 40 samples were prepared, 10 samples each for four mixing reagents. MTA (white) was mixed with four mixing reagents and condensed into split thickness molds after which it was allowed to set for 72 hours. After removing the samples from mold, samples were kept in freshly prepared Phosphate buffer saline solution at different pH (5.0 and 7.0) for 7 days after which they were removed from PBS and dried overnight before testing with Universal Testing Machine for compressive strength. Results were statistically analysed. Results: There was no significant difference found in compressive strength when comparison was done between sterile water and 1% Sodium hypochlorite at pH 7.0 and at pH 5.0. Within group comparison revealed, minimum changes in compressive strength with change in pH from 5 to 7 in Group I (MTA + Sterile water) while maximum was obtained in Group II (MTA + Metrogyl). In Group III (MTA + Sodium hypochlorite), a decrease in compressive strength was seen as pH decreased; however, the difference between pH 5 and 7 was not statistically different. Conclusion: All the groups tested showed a good compressive strength except MTA + Chlorhexidine group which did not set even after 7 days and amongst the group, MTA + Metrogyl exhibited better compressive strength. No significant difference was found at pH 5.0 and 7.0 among the group.