Very limited efforts have been made worldwide to use ferrochrome slag as fine aggregate in the concrete production and its behavior at elevated temperatures. Hence, an effort is being carried out to use the local ferrochrome slag as an alternate civil engineering material. In this study, the effect of using ferrochrome slag as a replacement of conventional sand (incremental range from 25% to 100%) on the properties of concrete (C40) at elevated temperature (range from 200°C to 1000°C with intervals of 200°C) was investigated. The concrete mixes were evaluated for workability, density, compressive strength, and split tensile strength at 28 days of curing. The density of the concrete is not changed significantly at 100% substitution of sand with FeCr slag. The mechanical properties of the concrete with FeCr slag at elevated temperature are compared with the Eurocode 2 and ACI recommendation for the siliceous concrete. The properties of the concrete with FeCr slag are found to be compatible with the code recommendations. The test results show that the compressive strength is increased with the increase of the percentage of ferrochrome slag replacing the conventional sand. The strength and weight of the concrete (with and without FeCr slag) are decreased with the increase of temperature. However, the strength reduction of the concrete with FeCr slag is less than that of normal weight concrete. Therefore, granulated FeCr slag may be used as an alternative green fine aggregate in the production of concrete.