Luminescent and non-luminescent nano materials are used today in a variety of lighting applications. One example is the thin layer of densely packed nano alumina between glass and phosphor in fluorescent lamps that serves to increase the efficiency, to improve the maintenance and to reduce the mercury consumption of the lamps. Further, non-luminescent nano materials may be used to form a thin conformal coating around phosphor particles that protects the phosphor particles and improves the efficiency and maintenance of fluorescent lamps. Luminescent nano materials have been the subject of extensive research in the last 15 years. For particle sizes below 20 nm, the optical properties of nano phosphors change, e.g. the exciton energy increases and perhaps even more important, scattering decreases. We have synthesized nano Y2O3:Eu of particle sizes down to 10 nm, derived its optical properties, and investigated its use in Hg-free fluorescent lamps based on the Xe-excimer discharge. The possibility of using nano phosphors, e.g. semiconducting nano phosphors as CdSe or rare-earth doped phosphors as LaPO4:RE in LEDs, will be discussed.