Mill scale is one of the byproducts which produced during the processing of steel. It is rich in iron (≥70%), has lower impurities and a stable chemical composition. The present research studies the effects of partial replacement of iron ore with different proportions of mill scale on the sinter charge. The results in this study showed that with an increase in iron ore substitution by mill scale at 3%, the rate of production increases from 21.94 to 25.50 ton/m2/day (16.2%), the vertical velocity increases from 0.0192 to 0.0217 m/min (13%) and the strength of the produced sinter increases from 88% to 90% (2%). Thus, the bulk density increases, but this negatively affects the reducibility degrees and apparent porosity of the produced sinter. At 2% mill scale, both reducibility and apparent porosity reach their highest values (66.42, 20.53%), respectively. On the other hand, the bulk density and softening interval decrease to the lowest values (2.3gm/cm3, 70%) , respectively.