In the title compound, [Cu(NO(3))(2)(C(6)H(6)N(4)S(4))](n), the Cu(II) atom, occupying a crystallographic inversion centre, is six-coordinated by two N atoms of two 2,2'-[1,2-ethane-diyl-bis-(thio)]bis-[1,3,4-thia-diazole] ligands in trans positions, and four O atoms from two symmetry-related opposite nitrate anions, which are asymmetrically bonded, resulting in a strong distorted octa-hedral geometry of the central atom. The ethane group is equally disordered over two sites via another inversion centre. The bridging bidentate 2,2'-[1,2-ethanediylbis(thio)]bis-[1,3,4-thia-diazole] ligands link the Cu(II) centres into a one-dimensional chain. The chains are inter-connected via inter-molecular S⋯O inter-actions [3.044 (4) and 3.084 (5) Å] and weak C-H⋯O hydrogen bonds, generating a three-dimensional supra-molecular structure.