Bimetallic joints of low alloy steel and stainless steel are widely used in high temperature corrosive environments. In the present investigation, an attempt has been made to investigate the weldability of AISI 4140 and AISI 316 by Gas Tungsten Arc Welding (GTAW) process with and without filler metal. The filler metal employed for joining these dissimilar metals was ER309L. Microscopic examination was carried out across the composite region of the weldment. Hardness and Tensile studies were performed to characterize the weldments for their mechanical properties. SEM fractography is carried out to get insight information on the mode of fracture. Also SEM/EDAX analysis has been performed to determine the structure-property relationships. © 2013 The Authors. Published by Elsevier Ltd.