The title compound, [BaCl(2)(C(2)H(6)SO)], forms a Ba(6)Cl(9) cluster in which the BaCl(2) units are connected via dimethyl-sulfoxide (DMSO) and chloride bridges. The central Cl atom of the Ba(6)Cl(9) cluster is located on a threefold inversion axis and is coordinated octa-hedrally to six barium cations. In the crystal, the clusters are arranged in rows, which are inter-connected by the DMSO mol-ecules, forming a three-dimensional network.