This paper investigates the effect of using crumb rubber (CR) from scrap tires as a partial replacement of sand on the mechanical properties of self-consolidating concrete. For this purpose, eight mixtures were developed with CR replacement varied from 0% to 40% (by volume of sand). The mechanical properties of the tested mixtures were investigated based on their compressive strength, flexural strength (FS), splitting tensile strength (STS), and modulus of elasticity (ME) at 7 and 28 day. The results indicated that increasing the CR replacement from 0% to 40% decreased the 28-day compressive strength, STS, FS, and ME by 66%, 56.6%, 42%, and 53.9%. However, all developed mixtures exceeded the minimum strength for structural applications (17 MPa). In addition, adding CR greatly enhanced the deformability of the tested mixtures. Also using higher percentage of CR (more than 30%) could contribute to develop semi-lightweight concrete.