The title compound, {(C10H10S8)[HgCl3]}n, is a sulfur-rich charge-transfer compound in which C10H10S8
+ cations and HgCl3 anions are assembled by S⋯S [3.371 (5)–3.588 (5) Å] and S⋯Cl [2.833 (4)–3.488 (4) Å] contacts, and by weak intermolecular C—H⋯Cl hydrogen bonds, forming a two-dimensional wave-like structure. The two C atoms of the –CH2—CH2– group in one of the cations are disordered over two sites with relative occupancies of 0.83 (2) and 0.17 (2).