The effect of copper implantation on the mechanical properties, such as hardness, fracture toughness, and residual stress of alumina is addressed herein. The implantation conditions are conducted at room temperature on the polycrystalline alumina with doses ranged from 3 x 10(16) to 10(17) Cu cm(-2) (110 keV). The ion profile distribution was examined by Rutherford backscattering spectroscopy. Surface morphology was observed directly using scanning electron microscopy. Using the X-ray diffraction, we determined the crystallographic nature of the precipitates formed after heat treatment, The residual surface compressive stresses produced by these implantations, as determined by an indentation technique, ranged from 950 to 1720 MPa. Implantation caused a modification in the mechanical properties and an increase in the residual stress. The average residual compressive stress in the implanted region increases with fluence.