The title compound, [Zn(C(12)H(11)N(2)O(4))Cl](n), contains a centrosymmetric dimetal tetra-carboxyl-ate paddle-wheel moiety in which the Zn(II) atom is square-pyramidally coordinated by four carboxyl-ate O atoms at the basal positions and one Cl(-) anion at the apical position. Each paddle-wheel unit is joined to four such neighbours through bridging dicarboxyl-ate ligands, producing a two-dimensional undulating layer parallel to (-101). Adjacent sheets are stacked in a parallel fashion to form a three-dimensional supra-molecular structure which is stabilized by inter-layer π-π inter-actions between benzene rings, with a centroid-centroid distance of 3.722 Å. The range of Zn-O bond lengths is 2.0440 (17)-2.1256 (15) Å and the Zn-Cl bond length is 2.2622 (6) Å.