Gamma-ray induced decomposition of some divalent nitrates, viz. Mg(NO3)2·6H2O, Ca(NO3)2·4H2O, Sr(NO3)2, Ba(NO3)2, Zn(NO3)2·6H2O, Cd(NO3)2·4H2O, Hg(NO3)2·2H2O, Mn(NO3)2·4H2O, Cu(NO3)2·3H2O and trivalent nitrates, viz. Al(NO3)3·9H2O, Fe(NO3)3·9H2O, Cr(NO3)3·9H2O, Y(NO3)3·6H2O, In(NO3)3·3H2O, La(NO3)3·6H2O, Ce(NO3)3·6H2O, Pr(NO3)3·6H2O, Bi(NO3)3·5H2O has been studied in solid state at room temperature. G(NO
) values (after applying appropriate dose correction) have been found to vary in the range 0.12–3.16 and 0.069–2.15 for divalent and trivalent nitrates respectively. G'-values were calculated by dividing G by the ratio of number of electrons in nitrate ion to the total number of electrons in the nitrate salt. Cation size, its polarizing power, available free space in the crystal lattice and the number and location of water molecules seem to play a dominant role in radiolytic decomposition. For Zn, Sr, In, La and Ce nitrates dose variation studies have been carried out.