The densification behavior of mixtures of nanocrystalline and conventional microcrystalline zirconia powders undergoing uniaxial pressing was investigated. The mixtures were obtained with ratios between 10 and 80 wt.% of nanoparticulate powder added to the microparticulate powder. Nitrogen and Mercury porosimetry were used to measure the pore size distributions of the compacts. The powders and the fracture surfaces of the compacts were observed via SEM. The results showed that compacts of the powder mixtures attain higher densities during pressing than the unmixed powders. The powder mixture with 80 wt. % of nanoparticles showed the better particle packing efficiency. A comparison between density values of uniaxial and isostatic pressing also was done and indicated that the best results were obtained by the isostatic method.