The title complex, [Ni(SO4)(C19H17N7)]center dot 2H(2)O or [Ni(SO4)(dpdapt)]center dot 2H(2)O [dpdapt is 6-phenyl-2,4-bis(2-pyridylamino)1,3,5-triazine], has a distorted trigonal-bipyramidal coordination where the equatorial plane contains the N atoms of the pyridine rings and one of the O atoms of the sulfate group, while the axial positions are occupied by the other O atom and the N atom of the triazine ring of the dpdapt ligand. The complex lies across a mirror plane. The H atoms of the NH group of the dpdapt ligand and of the solvent water molecule are involved in hydrogen bonds, which form an infinite two-dimensional corrugated sheet parallel to the ac plane. The water molecule is disordered over two positions; the site occupancy factors are 0.58 and 0.42.