Until about six years ago fluorescent lamp phosphor research was at a relatively low level. Calcium fluorochloro phosphate, activated by antimony and manganese, was the accepted phosphor for all but a few special applications. Its optical properties have been thoroughly investigated over the years and the color center formation responsible for its degradation during use could be effectively controlled by the use of cadmium. Since then, however, two factors have emerged that are having a profound effect on lamp phosphors. Restrictions on the use of some substances and, more importantly, the economic necessity to replace inefficient incandescent lamps with “acceptable” fluorescent lamp types are requiring the modification of present phosphors and the development of new ones. In order to make fluorescent lamps more “acceptable” for non-traditional applications, new demands are being placed on improved color rendition and more compact lamp designs. These demands must be met by phosphors with special spectral power distributions, thermal quenching properties, and resistance to degradation. Some of these demands are not well met with existing phosphors. In this paper we will review the progress that has been made in developing phosphors to meet these new requirements. Problems associated with some of these new phosphors will be discussed and the characteristics desired of phosphors yet to be developed will be described.