Amorphous ZrO2-Y2O3 precursors with different molar fractions of zirconium and itrum (from 0 to 100%) were obtained by coprecipitation from aqueous solution of nitrate salts by addition of ammonia to pH = 10.4. Crystallization of the starting amorphous samples was carried out using two different synthetic methods: hydrothermal treatment at 150 °C for 24 hours and annealing in air for 2 hours at temperatures of 400 °C, 600 °C, 800 °C and 1000 °C. Structural analysis of crystallization products was performed by X-ray powder diffraction (XRPD) and Raman spectroscopy, and morphology and the size of crystalline grains were monitored by a scanning electron microscope (SEM). The crystallization temperature of the amorphous precursors with an yttrium content of up to 20 mol% was determined using the differential scanning calorimetry (DSC). Quantitative analysis of crystalline products was carried out using Rietveld's refinement of the powder diffraction images. Precise determination of the parameters of unit cell of solid solutions ZrO2- and Y2O3-type was carried out by Rietveld's refinement of the diffraction images of the products of crystallization with an added standard (silicon). The obtained results have shown that the incorporation of less than 20 mol% of yttrium ions stabilizes the tetragonal polymorph ZrO2, while the incorporation of 20 or more mol% of the yttrium leads to stabilization of the ZrO2 cubic polymorph. The volume of solid cell ZrO2 type cell line grows linearly with the increase of yttrium, and this linear dependence is continued in the transition to a solid Y2O3 type solution. The results of SEM analysis and the analysis of broadening the diffraction lines have shown that the increasing heating temperature leads to the increase of crystalline grains, and the increasing the amount of the doped cation leads to the reduction of crystallinity.