The asymmetric unit of the title compound, (C(2)H(8)N)(2)[Cu(C(7)H(3)NO(4))(2)(H(2)O)(2)], contains one-half of a mononuclear [Cu(C(7)H(3)NO(4))(2)(H(2)O)(2)](2-) anion, one dimethyl-ammonium cation and one aqua ligand. The Cu(II) atom, lying on an inversion center, is coordinated by two symmetry-related N atoms and two O atoms from one pyridine-2,4-dicarboxyl-ate ligand and two symmetry-related aqua ligands and exhibits a distorted octa-hedral trans-[CuN(2)O(4)] coordination geometry. Multiple crystallographically independent O-H⋯O and N-H⋯O hydrogen bonds form a three-dimensional network in the crystal structure.