The title compound, {[Pr(C(2)H(6)OS)(8)](2)[Mo(6)Ag(6)S(24)]}(n), contains polymeric Mo(6)S(24)Ag(6) (2-) anions and [Pr(Me(2)SO)(8)](3+) cations, forming a one-dimensional polymeric Mo/S/Ag cluster. The anion assumes the conformation of a zigzag chain. The trivalent cations are arrayed amongst the anionic chains and are well separated from each other. Each Mo and Ag atom is coordinated by four S atoms in a distorted tetra-hedral geometry. The Pr(3+) atom is coordinated by eight dimethyl sulfoxide ligands, forming a polyhedron-shaped distorted square anti-prism.