The title compound, dirubidium dimanganese(II) tris-(tetra-oxo-molyb-date), Rb2Mn2(MoO4)3, was prepared by solid-state reactions. The structure can be described as being composed of MnO6 octa-hedra sharing corners with MoO4 tetra-hedra. The three-dimensional framework contains cavities in which the rubidium ions are located. The Rb(+) cations are within distorted nine- and 12-vertex polyhedra. The pairs of different Mn(2+) and Rb(+) cations are each located on threefold rotation axes.. Rb2Mn2(MoO4)3 is isotypic with compounds of the Cs2 M 2Mo3O12 (M = Ni, Fe) family. A comparative structural description is provided between the structure of the title compound and those of related phases. Differences with structures such as alluaudite are discussed.