Photolylsis of nickel azide at 308°K is compared with that of nickel azide under similar considerations. Nickel azide sample was prepared by adapting, the method of Brauer while nickel hydroxy azide was obtained by dehydrating the dihydrate of nickel azide cryslals, (Ni(N3)2)2Hp and exposing to atmospheric moisture. The rate of evolution of nitrogen at constant temperature and different intensities, decreases with time. The pressure of nitrogen produced with time varies directly as at all iutensities. The mte of photolysis at constant temperature at intervals of lime varies with intensity. Absence of pbotoconduction in the region reveals that excitons are the main reactants which get trapped in adjacent azide ions. This is evident in the linear dependence oflhe fate of photolysis on the intensity. The rate or photolysis of Ni(0H)N3 is observed.to be Jower than that of Ni(N3)2 by about a factor of l0.