The present study investigates the possibility of utilizing carbide lime waste, obtained from the generation of acetylene from calcium carbide, as a mineral filler material in various cement mortar mixes. The physical and chemical analysis of the waste were studied. Five mortar mixes containing various contents of carbide lime waste were prepared, tested, and compared with one control mix, to investigate the influence of the waste material on both fresh and hardened properties of mortars. The properties discussed were density, compressive strength, splitting tensile strength, flexural strength, and drying shrinkage. The strength and drying shrinkage values were determined at 3, 7 and 28 d, respectively. The results revealed that addition of carbide lime waste generally caused a reduction in both strength properties and density when compared with the control mix, in spite of the small influence on the drying shrinkage of some of the mortar mixes. However, the results obtained satisfy the minimum requirements of strength specified by British Standards, and hence it can be concluded that the material can readily be used for masonry mortar cement.