This paper study the feasibility of reusing waste iron powder (WIP) in mortar as both natural fine aggregate (NFA) and cement replacement material. Within this context, the physical and mechanical properties of mortar made with five percentage replacements of 0 %, 25 %, 50 %, 75 %, and 100 % for NFA by WIP and 0 %, 2.5 %, 5 %, 7.5 %, and 10 % for cement by fine waste iron powder (FWIP) are studied at 7, 14 and 28 days. Cube, briquette, and prism specimens for compression, tension, and flexural strength, respectively, tests were used. It is found that the workability decreases, and the density of mortar increase with the increased replacement percentage of NFA by WIP. The compressive, tensile, and flexural strength of mortar made with WIP are significantly higher than NFA. The maximum increase in strength of mortar is observed for 75 % WIP, which is 30 % for compressive, 35 % for tensile, and 37 % for flexural strength, respectively, relative to the control at 28 days. Conversely, when FWIP is used as a cement replacement material, all strength decreases with an increase in FWIP. The maximum decrease in strength is observed for 10 % FWIP, which is 40 % for compressive and tensile, and 16 % for flexural strength, accordingly, relative to the control at 28 days. The results presented in this study demonstrate that, to some extent, WIP and FWIP can be used in concrete/mortar production. Successful application of these waste materials may add economical benefit in the production of sustainable building material as well as conserve the natural aggregates.