High efficiency luminescence has been observed in fluorozirconate glasses doped with rare-earth ions. In particular terbium-activated fluorozirconate glasses 〈ZrF4-BaF2-ThF4〉: TbF3 at a temperature of 2 K show radiation efficiencies comparable to that of ZnS at 300 K. A range of concentration doping with Tb3+ from 0.1% to 15% was examined. The temperature and concentration dependences of the luminescence from these samples are reported. Lifetime data as a function of rare-earth concentration at room temperature are also presented. © 1981.