Diffusion bonding method is an alternate technique to join like and unlike materials with minimum dimensional tolerance. It is the solid-state process in which two metallic surfaces are made to contact at the elevated temperature and pressure. Diffusion bonding process provides high eminence joints without post-weld machining. The main process parameters of diffusion bonding embrace temperature, pressure and holding time. It is significant that the metallic surfaces should be spotless and free from oxides and nonmetallic films. In diffusion bonding technique microstructural changes were formed in the base metal which determines the mechanical properties of the bond at the interface. Diffusion bonding method can be used to weld the dissimilar materials with different chemical and mechanical properties. The present work reviews the influence of process parameters on diffusion bonded joints of dissimilar materials in the midst of and with no interlayer. Examination on the microhardness, lap shear and microstructure were made for various dissimilar diffusion bonded joints and finally some general conclusions are summarized.