In the title compound, [Cd(C(10)H(6)NO(2))(2)](n), the Cd(II) atom is coordinated by three O atoms and two N atoms from four quinoline-3-carboxyl-ate (L(-)) ligands, leading to a distorted trigonal-bipyramidal geometry. The L(-) ligands link the Cd(II) atoms into a plane parallel to (100), with one ligand being tridentate, coordinating via the N atom and chelating a second Cd atom, and the other being bidentate, bridging two Cd atoms via the N and one O atom.. This two-dimensional network extends into a double-layer network by π-π inter-actions, with centroid-centroid distances of 3.680 (2) and 3.752 (2) Å. Another type of π-π inter-action between pyridine rings [centroid-centroid distance = 3.527 (2) Å] leads to a three-dimensional supra-molecular architecture.