We have studied effects induced by γ-radiation and temperature in Mn-doped YAlO 3 crystals. The studies have been performed by means of optical spectroscopy that include measuring of optical absorption changes induced by γ-radiation and elevated temperature as well as thermally stimulated luminescence (TSL). It has been shown that under γ-irradiation of YAlO 3 :Mn crystals, along with the ionization of Mn A l 4 + ions (Mn A l 4 + ->Mn A l 5 + +e - ), some additional coloration processes take place. This additional coloration is characterized by a wide intense band centered at 26,000-25,000cm - 1 that is ascribed to color centers intrinsic to YAlO 3 lattice. This coloration is removed by the way of crystal warming at T>=350K, while the coloration caused by Mn A l 5 + ions is removed at higher temperature (T>=500K). The observed TSL glow of irradiated crystals reveals three peaks near 360, 400 and 500K that correspond to three types of traps. Parameters of the traps have been determined. The TSL emission corresponds to intra-center luminescence of Mn A l 4 + and Mn Y 2 + ions. The possible ionization and trapping mechanisms in YAlO 3 :Mn crystals are discussed.