Steel slag (SS) and ferrochrome slag (FCS) are industrial by-products that are produced in large quantities in Oman. According to recent studies, concrete containing these by-product materials as an aggregate has better mechanical properties than conventional concrete. However, very limited studies concentrated on the durability and environmental effect of concrete containing ferrochrome slag and steel slag as aggregates. In this study, locally produced FCS was used as coarse and fine aggregates in the production of concrete, while the SS was used as a coarse aggregate in the production of concrete. Therefore, the effect of using FCS aggregates to replace conventional aggregates (25%, 50%, 75%, and 100%) and SS aggregate to replace conventional coarse aggregate (50% and 100%) on the properties of concrete (C35) was investigated. The physical, chemical and mechanical properties of the slag materials and natural aggregates were determined to verify that they were within the standard limits. The concrete mixes were assessed in term of workability, density, compressive strength, splitting strength, flexure strength, modulus of elasticity, bond strength, chloride permeability, thermal conductivity, ultra-sonic pulse velocity, porosity, wet/dry cycles, acid and sulphate resistance, and corrosion resistance by impressed voltage test. The presence of FCS and SS aggregates improved the mechanical properties of the slag concrete compare to the conventional concrete. Porosity was remarkably reduced with the incorporation of various content of FCS aggregates. On the other hand, the porosity slightly increased with the increase of SS content. The chloride permeability of FCS concrete is lower than conventional concrete. On the other hand, SS concrete shows higher chloride permeability than conventional concrete. The utilization of slags in the concrete has resulted in increase the thermal conductivity. Higher ultrasonic pulse velocity was observed in higher content of FCS and SS aggregates. The use of FCS and SS aggregates enhanced the long-term compressive strength, resulting in better resistance to corrosion, wet/dry cycles, acid and sulphate attacks. The investigated results demonstrate that FCS and SS have a potential to be used an as an alternative aggregate in the production of environmentally friend and structurally applicable concrete.