Abstract: Zirconia-based dental ceramic is widely used for crown restoration, because of its superior mechanical properties and favorable biocompatibility. However, yttria-stabilized tetragonal zirconia (3YSZ), which is used in most dental crown restorations, has low translucency. This characteristic is unfavorable and results in low aesthetic quality of dental restoration. In this study, translucent 3YSZ dental ceramics were fabricated using nano-sized powder (20 nm) and high-temperature sintering (1500°C). The green bodies were slip casted and consolidated with cold iso-static pressing to create compact bodies. During the slip casting process different amounts of dispersing agent Polyethyleneimine (PEI) (0.2, 0.4, 0.6 and 0.8 wt%), were used to prevent agglomerates and create homogeneous suspensions. A minute amount (0, 0.1, 0.2, 0.3 and 0.4 wt%) of alumina was added into the suspension as sintering aid. The translucency or light transmittance of 3YSZ specimens was measured by an ultraviolet-visible spectrometer. Results showed that the 3YSZ specimen with 0.4 wt% alumina and 0.4 wt% PEI exhibited the highest light transmittance. The specimen also had larger grain size, because of excessive grain growth. The Vickers hardness of the specimens was insignificantly affected by the amount of alumina and PEI addition.