In the title coordination polymer, [Cu(C(9)H(8)NO(4))(2)](n), the Cu atom, located on a twofold rotation axis, is four coordinate in a distorted square-planar environment. Each 2,6-dimethyl-pyridinium-3,5-dicarboxyl-ate anion bridges two Cu atoms, forming a two-dimensional coordination polymer. A three-dimensional supra-molecular network is built from N-H⋯O hydrogen bonds involving the pyridinium NH and the carboxyl COO groups.