In this work, the effects of grain size and deformation temperature on mechanical properties and failure behaviour of 316L austenitic stainless steel (ASS) are investigated. The cold, warm and hot deformation are carried out at temperatures of 25, 500, and 800°C for the strain rate of 1$\cdot10^{-3}$ s$^{-1}$. The results show that strength and workhardening index of all samples decrease with increasing test temperature; however, decrement in strength and workhardening index is more less in coarse grained samples compared to the finer grained samples. This is due to dynamic strain ageing (DSA) occurred in the coarse grained samples which showed more pronounced serrated behaviour after testing at 500 or 800°C due to interaction of mobile dislocations and solute atoms.