Though electron beam welding (EBW) causes minimum destruction to the base metal, significantly different microstructure exists at weld zone. Rapid heating and cooling during electron beam welding results in dendritic microstructure, which lowers mechanical properties. In order to recover the original mechanical properties, post weld heat treatments (PWHT) needs to be performed after EBW. This paper presents effect of PWHTs on mechanical and microstructural properties of electron beam welded SAE 5137 H steel. Welded steel plates were processed through different heat treatments like stress relieving, normalizing and hardening & tempering. Micro-structural and mechanical testing were performed to characterize these specimens. It was perceived that, different PWHT’s can be employed and selection depends on final mechanical property requirement from the weld joint.