The asymmetric unit of the title salt, (C(4)H(14)N(2))[Cu(C(2)O(4))(2)], consists of one complex anion and two cationic half-mol-ecules, the other halves being generated by inversion symmetry. The Cu(II) atom in the anion is coordinated by two bidentate oxalate ligands in a distorted square-planar geometry. Inter-molecular hydrogen bonds, involving the NH groups as donors and O atoms as acceptors, are observed, which lead to the formation of a three-dimensional network structure.