Currently, the major challenges to researchers are enhancement of the machinability of difficult-to-machine (DTM) materials. The technology of cutting tool treatment is one of the approaches being implemented to overcome the challenges. Cryogenic and microwave treatments are two promising techniques to improve cutting tool properties in order to increase their effectiveness for enhancement of machinability. This paper presents the review of attempts made to enhance machinability of difficult-to-machine materials such as titanium alloys, nickel based alloys, ferrous alloys and composites materials using treated cutting tools. The objective of this work is to motivate the researchers and scholars to conduct further research, development, and innovations in this area.