Shotcrete or sprayed concrete is a kind of concrete that is usually used for temporary support in tunnels, wall surfaces and slope reinforcement. Shotcrete is executed in two ways, wet-mix and dry-mix which wet-mix is more commonly nowadays due to its performance advantages. Various approaches are used to enhance the mechanical characteristics of the shotcrete, including the use of fibers in the shotcrete. One of the important issues in recent years is environmental problems, therefore the use of waste from factories is the basis of many studies. Since iron slag is produced in large volume of iron and steel industry, as well as the very low production cost, slags become a common waste material that has been used in many engineering scopes, including civil engineering. In this research, the effects of using steel slag fiber on shotcrete mechanical properties was investigated and mechanical properties including compressive strength, tensile strength and flexural strength compared to non-fibrous shotcrete. In this study, in order to find the optimal percentage of the volume of steel slag fibers, five different types of mixes (including one mix for non-fibrous shotcrete) have been used. Experiments were carried out on specimens at 7 and 28 days after the execution of the shotcrete in order to compare the initial and final strengths of the results. The results of the experiments show that, the highest strength in 7 days is obtained by adding 1 kg/m 3 steel slag fibers and in 28 days is obtained by adding 5/0 kg/m 3 steel slag fibers. It was also observed that, adding more dosage of this amount of steel slag fibers to shotcrete mix, significant reduction in strengths properties gained