Stress block parameters play an important role in the design of structural elements. The objective of this study is to derive the complete stress-strain behavior for steel fiber reinforced ground granulated blast furnace slag (SFGGBS) concrete in which cement was partially replaced with optimum percentage of GGBS and steel fiber. Parameters such as compressive strength, modulus of elasticity, Poisson’s ratio and ductility of GGBS concrete were compared with ordinary Portland cement (OPC) concrete. GGBS concrete was found to have increased the ductility compared to OPC concrete. Steel fiber was added to GGBS concrete to study the ductility and cracking behavior, wherein the SFGGBS concrete was found to have an increased ductility than that of OPC concrete. Stress block parameters were developed for steel fiber reinforced GGBS concrete.