The complete molecule of the dinuclear title compound, [Hg(2)I(4)(C(7)H(4)S(3))(2)], is generated by crystallographic inversion symmetry. The complex has a dimeric structure in which each Hg(II) ion adopts a tetra-hedral geometry and is coordinated by two bridging I atoms, one terminal iodide ion and one thio-carbonyl S atom (C=S) of the ligand. The square plane formed by the Hg and I atoms and their symmetry counterparts makes a dihedral angle of 89.66 (3)° with the DDT plane. There is no classical hydrogen bonding, but weak S⋯S inter-actions of 3.4452 (7) and 3.6859 (7) Å maintain the cohesion of the crystal structure.