Stabilizied zirconia nanoparticles due to their unique properties find application as solid electrolytes, gas sensors, catalysts, high-temperature corrosion resistant materials. The aim of present work was comparison of properties and sinterability of stabilizied ZrO2 prepared by molten salts (MS) and microwave (MW) synthesis using Zr or Ce salts as precursors. The MW synthesis was carried out in a Masterwave BTR, Anton Paar apparatus by heating salts solution at temperature in the range of 150–190 oC during 20 min. The MS synthesis was carried out by heating mixture of the precursors at temperature in the range of 400–800 oC during one or two hours. The prepared by the both methods YSZ crystalline nanoparticles containing 3 mol% Y2O3or 10 mol% CeO2 consisted from t-ZrO2 and c-ZrO2 phase. The specific surface area of the nanoparticles prepared by MS and MW synthesis was in the range of 124–146 m2/g and 90–117 m2/g respectively in dependence on the synthesis parameters. Crystallite size of nanoparticles was in the range of 4–14 nm. The prepared samples were densified by using spark plasma sintering (SPE-825-CE, SPS Syntex Inc.). Densification of YSZ and CSZ nanoparticles started at 850 oC and samples with finegrained microstructure with relative density of 98 and 96% respectively were obtained at 1300 oC. YSZ nanoparticles prepared by MS process had better sinterability with respect to CSZ nanparticles prepared by MW process. The research was supported by Latvian National Research Program IMIS2.