This paper reviews the commonly used coating materials and surface treatments for tribological applications. The coating materials considered are plastics, such as polytetrafluoroethylene, polyamide-imide, polyphenylene sulfide, and polyimide; molybdenum disulfide; graphite; cadmium oxide-graphite-silver; calcium fluoride-silver-glass-nickel-chrome; hard chrome; electroless nickel; silver; and some selected carbides, nitrides, borides, and oxides. Surface treatments considered are carburizing, nitriding, carbonitriding, boriding, induction hardening, flame hardening, and laser hardening. Some examples of industrial applications are presented.