The title compound, [Zn(H(2)O)(6)][Zn(C(7)H(4)NO(4))(3)](2), consists of two [Zn(py-2,3-dcH)(3)](-) anions (py-2,3-dcH is 3-carboxy-pyridine-2-carboxylate) and one [Zn(H(2)O)(6)](2+) cation. The anion is a six-coordinate complex located on a threefold rotation axis with a slightly distorted octa-hedral geometry around Zn(2+) ion. The cation is also six-coordinate with an octa-hedral geometry around the Zn atom, located at a axis. Non-covalent inter-actions such as π-π stacking [centroid-centroid distance = 3.828 (4)Å] and O-H⋯O hydrogen bonds play important roles in stabilizing the supra-molecular structure.