Iron ore tailings (IOT) are the mining waste left after extraction of iron ore. The particles of IOT have grain size of sand and since there is a problem of disposal it can be used as an ingredient in concrete. Ground granulated blast furnace slag (GGBFS) is a waste obtained from blast furnace. Since it has fineness similar to cement, it can be used as an ingredient in concrete. In the present experimental investigation, natural sand is partially replaced by IOT at (10%, 20%, 30% and 40%) different percentages. The cement part was substituted with different percentages of the GGBFS (5%, 10%, 15%, and 20%). Tests on fresh concrete and hardened properties were conducted. Slump cone test and compaction factor test was carried out to find the workability of concrete. Compressive strength test, split tensile strength test, flexural strength test and durability test was conducted to find the strength of concrete. Superplasticizer (SP) was added to have good workability for all replacement levels. The concrete with 20% IOT and 10% GGBFS achieved more split tensile (3.86 N/mm2), compressive strength (53.47 N/mm2) and flexural strength (7.33 N/mm2) than normal concrete. In the durability test of cube specimen, as the substitution % of the concrete mixture increases, the water absorption rate increases. Mix design is carried out for M40 grade concrete.