The title compound, [(C12H13N2)2[Mo5O16]]n, was synthesized under hydrothermal conditions. The structure contains a two-dimensional layer, constructed from [(Mo4O14)n]4n- chains linked through MoO6 octahedra, which lie across twofold axes. The [(Mo4O14)n]4n- chain consists of [Mo4O14]4- clusters connected to one another by sharing their MoO5 square-pyramidal and MoO6 octahedral vertices in an anti disposition. The layers are linked by the cation, to which they are connected via N-H...O hydrogen bonds.