A review is reported of the various types of laser treatments which can be performed. The influence of infrared, visible and UV radiations on the surface composition, microstructure, morphology and properties of a lot of materials is investigated. Representative examples are given, to illustrate the various possibilities, e.g. laser cladding on metallic materials, remelting of ceramic, surface modification of ceramics for bonding to metals, surface amorphization of organic materials, formation of conductive area on polyimide films, and so on. Directions in which works are currently being pursued are mentioned.