In the title compound, [Ni(C(12)H(9)O(2))(2)(C(7)H(6)N(2))(2)]·H(2)O, The Ni(II) cation is located on a twofold rotation axis and is six-coordinated in a distorted NiN(2)O(4) octa-hedral geometry. The asymmetric unit consists of a nickel(II) ion, one 2-(naphthalen-1-yl)acetate anion, a neutral benzotriazole ligand and one half of a lattice water mol-ecule. The crystal packing is stabilized by O-H⋯O and N-H⋯O hydrogen bonds. The title compound is isotypic with its Cd(II) analogue.