Dimeric mol-ecules of the title compound, [Ru(2)Cl(4)(C(12)H(18))(2)], are located on a crystallographic centre of inversion with one mol-ecule in the asymmetric unit. The hexa-methyl-benzene rings are in an η(6)-coordination to the ruthenium centres, which are bridged by two chloride ligands. In addition, the ruthenium centres are bonded to another chloride ligand. The aromatic rings and the Ru(2)Cl(2) four-membered ring enclose a dihedral angle of 55.85 (6)°.