The effect of incorporation Al2O3-NbC nanopowders to reinforce 3Y-TZP matrix and the influence on mechanical properties of 3YTZP-Al2O3-NbC nanocomposites obtained by conventional and spark plasma sintering (SPS) was investigated. The nanometric powders of Al2O3-NbC were prepared by reactive high-energy milling, deagglomerated, leached with acid, and added to the 3Y-TZP matrix in the proportion of 5 vol%. The final powders were dried under airflow, compacted and sintered at the temperature range of 1300-1500 °C. The effect of sintering technique and final temperature on the microstructure and mechanical properties, such as hardness, toughness and Young's modulus were analyzed. An important mechanical value obtained in all materials reinforced with Al2O3-NbC nanopowders is the fracture toughness, which differ significantly of the 3Y-TZP monolithic material (5.2 MPa•m 1/2). The nanocomposites sintered conventionally at 1450°C show the higher fracture toughness (8.7 MPa•m 1/2). Microstructure observations indicate that NbC nanoparticles are dispersed homogeneously within 3Y-TZP matrix and limited their grain growth. However, the partial oxidation of the NbC in the surface of the nanocomposites found a limit in the conventional sintering temperature, since the samples sintered at 1500°C showed a reduction in fracture toughness.