The objective of this paper is to evaluate the light rare earth influence on hydrothermal ageing behaviour of ZrO2 - CeO2 - Y2O3 ceramics at low temperatures ( 200 - 300 degreesC). With this purpose zirconia samples doped with 2 mol% of yttria and 10 mol% of fight rare earth oxides were prepared using light rare earth concentrates. Powders were synthesized by the coprecipitation route. Apparent density values were determined by Archimedes method. The sintered pellets were characterized, before and after the ageing tests at 250 degreesC for 100 hours, by X - ray diffraction (Rietveld refinement), Vickers indentation technique, scanning electron microscopy and grain size determination. Results indicate that fight rare earth presence has no significant effect on ZrO2 - CeO2 - Y2O3 ceramics performance. It was verified that the high purity oxides, that present high costs, are not required to obtain zirconia ceramics with better properties.