Abstract The paper clarifies the specific mechanical properties of single crystal YSZ through applying the nanoindentation examination and the finite element analysis with theoretical ultrasonic measurements. The obtained results demonstrate that the lack of precise determination of the Poisson's ratio results in the significant discrepancy between output of nanoindentation and ultrasonic measurements of Young's modulus. It was observed that the anisotropy varied depending on the elastic or plastic measurements. From the variation of the load velocity in nanoindentation, it was asserted that Young's modulus and hardness were expressed by the exponential function of load velocity, i.e., time.