This article presents the compressive strength and workability of cement mortar (CM) containing recycled asphalt pavement (RAP) as fine aggregate replacement. The effect of the RAP replacement, water to cement ratio, curing time, and aggregate water absorption on compressive strength and flow workability are reported. The results show that the mixing water and mixing time play a significant role in the compressive strength and unit weight of CM containing RAP. The RAP has a higher water absorption and slower rate of water absorption than those of sand. The flow workability of CM increases with RAP replacement due to the unabsorbed water at the initial mixing stage. The main negative factors that affected the compressive strength of CM containing RAP as a fine aggregate replacement are revealed. The unabsorbed water at the initial state of mixing before hardening causes increased flow workability and decreased compressive strength. The findings from this research will promote the mix design approach of CM containing RAP as a fine aggregate replacement, for moving toward increased applications of recycled materials in a sustainable manner in civil engineering construction.