In the title compound, [Zn(C(18)H(14)N(4))(2)(H(2)O)(4)](NO(3))(2)·1.49H(2)O, the Zn(II) atom, lying on an inversion center, is coordinated by two N atoms from two N,N'-bis-(pyridin-3-yl-methyl-idene)benzene-1,4-diamine ligands and four water mol-ecules in a distorted octa-hedral geometry. The nitrate anion is disordered over two sets of sites, with an occupancy ratio of 0.744 (4):0.256 (4). The uncoordinated water mol-ecule is also disordered with an occupancy factor of 0.744 (4). O-H⋯O and O-H⋯N hydrogen bonds link the complex cations, nitrate anions and uncoordinated water mol-ecules into a supra-molecular layer parallel to (102).