Laser remelting enables the solidified layers to melt and solidify rapidly again, thus could improve the relative density and surface quality. It is a type of surface modification technologies, and has been widely used in traditional manufacturing processes. Recent researches showed that laser remelting could be used to refine the microstructure, reduce the porosity and improve surface quality of SLM processed metals and alloys. Laser remelting technology can also improve the mechanical properties such as hardness and ductility. This paper made a thorough literature survey and summarized how laser remelting could affect the porosities, microstructures, surface qualities and residual stress of SLM processed metals and alloys. Furthermore, the working parameters of laser remelting and their influences on the porosities, microstructures, surface qualities and residual stress are introduced.