Oxy-fluoride glass-ceramics containing rare earths ions Nd^3+/Ho^3+ were fabricated. Heat treatment for two different times caused the precipitation of calcium-fluoride nanocrystals in which doped Nd^3+/Ho^3+ ions were concentrated. The scanning electron microscopy (SEM) images were obtained, and a uniform nanocrystal distribution was observed. The transmission electron microscopy (TEM) images of the best sample proved the existence of nanocrystals. Optical properties and the up- and down-conversion processes among Nd^3+ ions in oxy-fluoride glass-ceramics have been investigated. The absorption intensities of the sample which was heat treated for two more hours were stronger. The up- and down-conversion emission spectra of the best sample under different excitation wavelengths have been explained.