This paper reports that Zn ion implantation to a dose of 1 × 1017 ions/cm2 was performed on highly c-axis-orientated ZnO thin films deposited on Si (100) substrates by the sol-gel technique. After ion implantation, the as-implanted ZnO films were annealed in argon ambient at different temperatures from 300−500 oC. The effects of ion implantation and post-implantation annealing on the structural and luminescent properties of the ZnO films were investigated by x-ray diffraction, photoluminescence (PL). Results show that the intensities of (002) peak and photoluminescence (PL) were evidently decreased by Zn ion implantation. The recovery of (002) peak and photoluminescence occurs at ~300oC.