A new salt, p-xylylenebis(tetrahydrothiophenium) bis(triiodide) C16H24I6S2, was prepared. The molecular structure of the salt was studied by X-ray diffraction; the factors that form the crystal packing represented by...Ct...I-3...I-3...Ct... type chains (Ct is cation) were identified. The stability of p-xylylenebis(tetrahydrothiophenium) diiodochlorides and triiodides was estimated by spectrophotometry using the average iodine number function (n) over barI(2).