[en] This work reports and discusses the results for the crystalline cubic phase formation and stabilization of zirconia as a function of the temperature and yttrium and rare earth oxides mixture (YRE) content. The raw materials were of Brazilian origin. The powder mixtures were obtained from the yttrium and rare earth hydroxides and hydrous zirconia coprecipitation. These powder mixtures were dried at 100 C in air. The DTA/TGA analyses showed that the temperature of the formation of ZrO₂ crystalline phases was a function of the YRE content. The crystalline phase evolution of these powders as function of the treatment temperature was studied by X-ray diffraction. It is concluded that for this studied YRE-ZrO₂ system, the zirconia cubic phase can be stabilized in the temperature of 500 C and remains stable at 1400 C. (orig.)