The purpose of this study was to compare the compressive strength, diametral tensile strength and microhardnss of several selfadhesive resin cements (Rely-X U200, Clearfill SA Luting, G-CEM LinkAce, Maxcem Elite, PermaCem 2.0, and Zirconite) using different activation modes (self-cured, light-cured) and testing time (immediately, 24 h, thermocycling). Specimens were prepared for the compressive strength (Ø 4×6 mm) and diametral tensile strength and microhardness (Ø 6×3 mm) according to ISO standards. The strength after 24 h was higher than immediately after. In addition, G-CEM showed the highest values. In terms of the activation modes, Rely-X U200, PermaCem 2.0 had higher values in the light-curing than the self-curing. In conclusion, all cements demonstrated clinically available strength values and revealed differences in strength according to their composition, testing time and activation mode. Furthermore, correlation was found between the microhardness (degree of conversion) and mechanical strengths of the cements tested.