Thin films of Er3+/Yb3+: LiNbO3 were deposited on sapphire (0001) substrates using a spin-coating process. A deposited solution was prepared by a non-aqueous sol-gel method using 2-methoxyethanol, metallic lithium, niobium(V) ethoxide and erbium and ytterbium acetates. Two starting compositions of LiNbO3 solution (1:1 or congruent) were tested in order to minimize the present of secondary (Er/Yb)NbO4phases. The effect of different temperature (800oC or 1000oC) and different used atmosphere (air or oxygen) during the films crystallization was also investigated. Rapid annealing (at 1150oC with the heating rate 55oC.s-1/) was also tested and its influence on secondary phases crystallinity and luminescence of Er3+/Yb3+: LiNbO3 was established. The thin films were characterized by X-ray diffraction analysis, scanning electron microscopy and photoluminescence spectroscopy.