The influence of processing parameters (pH value, type of anion, and reaction temperature) on the properties of hydrous zirconia, prepared by hydrolytic condensation of zirconium n-propoxide, has been investigated. The obtained amorphous samples and their crystallization products were characterized using BET analysis, TG analysis, DSC, XRD, FT-IR and laser Raman spectroscopy. Specific surface area of the samples increased with an increase in the reaction temperature and processing pH value up to 7.5. Further increase in the pH value caused a small decrease in the specific surface area of the samples. Most of the crystallization products, obtained on calcination of the samples at 400 o C, contained tetragonal (t-)ZrO 2 as the dominant phase. The stability of t-ZrO 2 to the influence of pressure (500, 1000 and 1350MPa) showed to be pH dependent. On the other hand, the stability of t-ZrO 2 to the influence of temperature (600 and 800 o C) could not be attributed to the influence of the pH value alone. Lattice strains in the t-ZrO 2 products increased almost linearly with an increase in the pH value, while the crystallite size showed to be independent of the pH value. Mechanical treatment of the hydrous zirconia samples caused an increase in both the crystallite size and t-ZrO 2 content in the corresponding crystallization products, but the stability of t-ZrO 2 remained approximately the same. It was concluded that the observed differences in the t-ZrO 2 stability resulted from the combining influences of more than one experimental factor.