The suspended and dissolved particles presented in the water and wastewater in the size of 1-1000 nm which is more toxic and it causes severe effects to the aquatic life and living organisms. Nanotechnology is the method, which is newly developed in this world, to remove the very tiny particles presents in the water as well as wastewater with the help of nano-particles. Many nano-particles were used to remove the toxic contents presented in water and wastewater such as heavy metal concentration, dyes and some of the virus and bacteria etc. Compared to various nano-materials, Graphene is the type of smart material which is derived from the graphite, most widely used in all industrial sectors for various purposes. This review paper discussed about the importance of graphene usage in water and wastewater treatment technologies in recent days.