The title copper coordination polymer, [Cu(3)(C(8)H(4)O(4))(2)(C(8)H(5)O(4))(2)(C(10)H(8)N(2))(2)](n), was synthesized by reacting Cu(NO(3))(2), isophthalic acid and 1,10-phenanthroline under hydro-thermal conditions. The trinuclear unit presents a central almost planar CuO(4) chromophore with the cation on a symmetry center, and two symmetry-related CuN(2)O(3) groups with the metal centre in a distorted square-pyramidal environment. These units are bridged by isophthalate ligands into one-dimensional double-chain coordination polymers which are, in turn, connected by various π-π stacking inter-actions (face-to-face distance ca 3.45 Å) and O-H⋯O hydrogen bonds, forming a three-dimensional supra-molecular network.