Cement is the most consumed building material in the world. However, cement manufacture is responsible for 5–7% of the world CO2 emissions. In this paper, cement was partially replaced by styrene-butadiene rubber (SBR) polymeric latex in order to reduce cement consumption. Besides, effects of SBR addition on the strength and physical properties of plain mortar exposed to three different curing regimes are presented. Three different curing regimes were applied to the 40 × 40 × 160 mm prismatic mortar specimens: (I): Specimens were cured in water until the test age (CW), (II): after demoulding, specimens were immersed in water for 2 days and kept in ambient temperature until the time of the test (2DWA) and (III) involved 2 days of water curing followed by 1 day in an oven at 50°C and subsequentely placing in ambient temperature until the test time (2W1OA). Results showed that combining 2 days of water curing followed by ambient temperature curing (2DWA) along with 3% SBR polymer content showed good performance in terms of compressive strength, water absorption and void content. Moreover, a good performance in terms of flexural strength was observed by combining 2W1OA curing regime with 2% SBR content. However, the detrimental effect of water curing regime (CW) in terms of compressive and flexural strength was also observed with the increase of SBR ratio.