The present work critically reviews the current state of the art in micro/nano welding and its future applications in various micro systems. New developments such as the electron beam microwelding, leaser microwelding resistance microwelding, solid state ultrasonic welding, microjoining by adhesive bonding, micro-electromechanical systems, micro-total analysis systems. Micro/nano welding of dissimilar materials have been discussed. These techniques are promising and are expected to be used in future joining applications. As micro/nano techniques are affected by even minutest particles of dust special considerations need to be given to the development of improved machines for nano welding.