The asymmetric unit of the title compound, [Rb(C(7)H(3)N(2)O(6))](n), comprises an Rb cation and a 3,5-dinitro-benzoate anion. The Rb cation is eight-coordinated by O atoms from five 3,5-dinitro-benzoate anions. On the other hand, each 3,5-dinitro-benzoate anion links five Rb cations with the carboxyl-ate groups as μ(3)-bridging. The metal atom is firstly linked by the carboxyl-ate groups into a chain along the c-axis direction, which is further linked by bonds between the Rb and nitro O atoms, giving a three-dimensional framework.