The effects of UV, gamma irradiation, annealing in air (700-1300 K) and N2+H2 gas mixture (1700 K) on optical and lasing properties of Nd-doped YAlO3 (YAP-Nd) laser crystals were investigated. The crystals were grown by the Czochralski technique from iridium crucibles in 98% Ar+2%O2 atmosphere. This article details the results of this investigation.