The crystal structure of the title compound, [Rb(C18H36N2O6)]3RbSn9, consists of deltahedral [Sn9]4– cluster anions, Rb+ cations and cryptand molecules, which partially sequester the cations. Those cations, which are not coordinated by cryptand molecules, are neighboured directly to the [Sn9]4– clusters and interconnect them to form ∞1[RbSn9]3– chains. These chains extend parallel to [001] and are arranged in a pseudo-hexagonal rod packing, separated by the Rb-cryptand complex cations.