The title compound, [Zn{(CH3)2SO}6]I4, is a one-dimensional supra-molecular polymer along a threefold rotation axis of the space group. It is built up from discrete [Zn{(CH3)2SO}6](2+) units connected through non-classical hydrogen bonds to linear I4 (2-) polyiodide anions (C-H⋯I = 3.168 Å). The Zn(II) ion in the cation has an octa-hedral coordination geometry, with all six Zn-O bond lengths being equivalent, at 2.111 (4) Å. The linear polyiodide anion contains a neutral I2 mol-ecule weakly coordinated to two iodide ions.