In the title compound, {[Cd(2)(C(17)H(6)O(9))(C(18)H(10)N(4))(2)(H(2)O)(2)]·H(2)O}(n), the Cd(II) atom is seven-coordinated by five O atoms from two different 4,4'-carbonyl-bis(benzene-1,2-dicarboxyl-ate) (BPTC) anions and one water mol-ecule, and by two N atoms from one chelating dipyrido[3,2-a:2',3'-c]phenazine (L) ligand in a distorted penta-gonal-bipyramidal geometry. The BPTC anions link the Cd(II) atoms, forming a one-dimensional chain structure. The L ligands are attached on both sides of the chain. A twofold rotation axis passes through the complex molecule. The crystal structure involves O-H⋯O hydrogen bonds.