The influence of ceria (CeO2: 0…3,56 wt. %) and sintering method (pressureless sintering in air, hot pressing in Ar) on the phase composition, microstructure, and properties of alumina-zirconia ceramics was investigated. The sintering method was found to determine the dual role of CeO2. Hot pressing facilitated the reduction of Ce4+ до Ce3+ and the formation of plate cerium hexaaluminate CeAl11O18, identified by XRD and EDS. Pressureless sintering led to the stabilization of the cubic ZrO2 phase (c-ZrO2). Hot pressing achieved high relative density (>99 %) and practically no open porosity, while pressureless sintering resulted in porosity up to 5 %. Hardness decreased with increasing CeO2 content for both methods. Fracture toughness in pressureless sintered ceramics was primarily controlled by porosity. In contrast, KIC increased with CeO2/CeAl11O18 content in hot-pressed materials, reaching a maximum of 7,5 ± 0,2 MPa·m1/2, demonstrating the effectiveness of CeAl11O18 as a toughening phase. The results indicate that hot pressing is the preferred method for producing CeAl11O18-toughened Al2O3–ZrO2 ceramics.