Photoluminescence (PL) of sapphire single crystals as received and preirradiated by low energy Ar+ ions and electrons has been studied to reveal a relationship between sapphire charging under electron beam irradiation and radiation-induced defect formation. The photoluminescence spectra were obtained using a confocal microscope excitation wavelength of 445 nm as well as by a nonconfocal method with excitation at a wavelength of 355 nm. The lines observed in PL spectra for all samples are associated with both intrinsic and impurity defects. It has been established that preliminary ion irradiation leads to disordering of the near-surface region of the sample resulting in a significant increase in the photoluminescence intensity. Preliminary electron irradiation can lead to a change in the charge state of defects that initially exist in the crystal. Keywords: radiation-stimulated defects, sapphire photoluminescence, ion and electron irradiation.