In the title compound, [Co(C(14)H(8)O(4))(C(18)H(10)N(4))](n), the Co(II) atom is six-coordinated by four O atoms from two different biphenyl-2,2'-dicarboxyl-ate ligands and two N atoms from the bidentate dipyrido[3,2-a:2',3'-c]phenazine ligand in a distorted octa-hedral geometry. The Co(II) atoms are bridged by the biphenyl-2,2'-dicarboxyl-ate ligands to form a one-dimensional chain structure. π-π inter-actions between neighbouring chains result in a two-dimensional supra-molecular network (centroid-to-centroid separation = 3.381 Å).