The title compound, {(C(13)H(22)N(4))[Ag(2)I(4)]}(n), was prepared by reaction of 1,3-bis-(N-ethyl-imidazolium-1-yl)propane iodide with silver (I) oxide. In the 3,3'-diethyl-1,1'-(propane-1,3-di-yl)di(1H-imidazol-3-ium) cation, the dihedral angle between the imidazole rings is 49.3 (1)°. In the [Ag(2)I(4)](2-) anion, each Ag(I) atom is bonded to three iodide anions, the two Ag(I) atoms and two of the iodides forming Ag(2)I(2) square-planar (r.m.s. deviation = 0.01 Å) units·The remaining two iodides, which are placed on opposite sides of the square, together with their centrosymmetric counterparts, link the square-planar Ag(2)I(2) units into {[Ag(2)I(4)](2-)}(n) polymeric chains via Ag-I bonds.