In the title one-dimensional coordination polymer, [Ag(NO(3))(C(12)H(6)N(2)O(2))](n), the Ag(I) atom is penta-coordinated by two N atoms from a 1,10-phenanthroline-5,6-dione (phen-dione) ligand, one O atom from the nitrate anion and two O atoms from another phen-dione ligand. The coordination environment around silver is slightly distorted square-pyramidal. Inter-estingly, the Ag-O distances to the phen-dione ligand are different [Ag-O = 2.612 (6) and 2.470 (5) Å]. The one-dimensional chains run parallel to [101] and are further inter-connected by weak hydrogen bonds (C-H⋯O) and π-π stacking inter-actions [centroid-centroid distances 3.950 (4) and 3.792 (4) Å], forming a three-dimensional supra-molecular network.