This document presents a study that evaluates the physical and mechanical properties of concrete using fly ash and ferro sand. Fly ash is a byproduct of coal power plants and ferro sand is a byproduct of the steel industry. The Taguchi method was used to design the experiments to determine the optimal mix proportions. Nine concrete mixes were tested according to an L9 orthogonal array, varying the percentage replacements of cement with fly ash (10%, 20%, 30%) and natural sand with ferro sand (15%, 30%, 50%). The fresh and hardened concrete properties tested included slump, unit weight, compressive strength, flexural strength, and splitting tensile strength. The results showed that fly ash decreases concrete strength while ferro sand increases strength. The