In this study, the effect of 3% yttria stabilized zirconium oxide (ZrO₂) addition at different rates on the hydroxyapatite obtained from waste sheep femur bones (SHA) was investigated. For this purpose, 4 different composites were prepared and after pressing, they were sintered at 1100-1300^oC for 4 h. For pure SHA, while density, partial density, hardness and brittleness index increased with increasing sintering temperatures, the highest diametral tensile (8.23±0.28 MPa) and compression strength (82.48±5.50 MPa), and fracture toughness (0.70±0.11 MPam^1/2) were obtained at 1200^oC.  Sintering of pure sheep HA at 1300^oC caused decomposition into beta tricalcium phosphate (β-TCP), alpha tricalcium phosphate (α-TCP) and calcium oxide (CaO) phases. For this temperature, the rate of decomposition in pure SHA was calculated as 4.1%. Decomposition rate in KHA-ZrO₂ composites increased up to 48.1% with increasing sintering temperature and ZrO₂ ratio. Two different calcium zirconate (CaZr₄O₉ and CaZrO₃) phases were detected in KHA-ZrO2 composites, and it was concluded that the increase in decomposition in these composites was due to the CaZrO₃ phase. The KHA-2.5ZrO₂ composite sintered at 1200oC had the best properties among the KHA-ZrO₂ composites. The fracture toughness of this composite is 1.25±0.08 MPam1/2, and the vertical and horizontal compressive strength values are 122.0±2.12 MPa and 11.21±0.42 MPa. However; due to insufficient fracture toughness of KHA-ZrO₂ composite, it is recommended to be used in applications that do not require load resistance in the human body.