Since Y2O3 is a stable material with poor solubility in water, densification is achieved at high temperatures. In the present study, we demonstrate that a cold sintering process combined with conventional sintering (CSP-CS) using a solution of yttrium nitrate (Y(NO3)3‧ 6H2O) could improve the packing density and further enhance the densification of Y2O3. The weight loss, phase characteristics, microstructures and densification behaviour of the specimens are investigated as a function of yttrium nitrate addition. In addition, the densification process of the Y2O3 ceramics during CSP are explained through each step.