Persistent luminescence (PeL) was obtained from glasses with the composition (75NaPO3-25CaF2) (in mol%) by adding PeL microparticles SrAl2O4:Eu2+,Dy3+ in the melts using the direct doping method. The glasses exhibit a strong PeL although they crystallize upon quenching. The crystallization was related to the poor thermal stability of the glass, and also to the extensive loss of fluorine during the glass preparation. The use of quartz crucibles and the long process time used to prepare glasses using the direct doping method are responsible for the fluorine losses.