The microstructural evolution of a single crystal of yttria-stabilized zirconia (YSZ) implanted with Ti has been studied by cross-sectional transmission electron microscopy (TEM). The implantation of 180 keV Ti ions to a dose of 131017 ions/cm2 was completed at room temperature. After annealing at 1100℃ in an Ar atmosphere for 2h, a phase transition from the fluorite structure of ZrO2 to an isometric pyrochlore structure-type, A2B2O7, occurred due to cation ordering. High-resolution TEM revealed nanodomains of pyrochlore, Y2(TixZr12x)2O7, with a>10.2460.05 Å. The nanodomains of the pyrochlore phase, embedded within the YSZ fluorite substrate, occurred in a depth range from 45 to 105 nm below the surface, which corresponds to Ti concentrations from; 10 to; 15 at. %. The nanoscale pyrochlore precipitates and the YSZ matrix have a completely coherent orientation.