The asymmetric unit of the title compound, (C(4)H(5)N(2)O)(2)[Cu(2)Cl(6)(C(4)H(4)N(2)O)(2)]·2H(2)O, consists of one cation, one half of a centrosymmetric dianion and one water mol-ecule. The centrosymmetric dianion formed by dimerization in the crystal structure has neutral pyrimidin-2-one ligands coordinated to each copper(II) centre through Cu-N bonds. The Cu atoms each have a distorted trigonal bipyramidal geometry, with the N atom of the pyrimidin-2-one ligand in an axial position, and dimerize by sharing two equatorial Cl atoms. N-H⋯Cl, O-H⋯Cl and N-H⋯O hydrogen bonds connect the anions, cations and water mol-ecules, forming a three-dimensional network.