The title compound, {(C(2)H(10)N(2))[Cd(2)(HPO(4))(3)]·H(2)O}(n), was synthesized under hydro-thermal conditions. The structure of this hybrid compound consists of CdO(6), CdO(5) and PO(4) polyhedra arranged so as to build an anionic inorganic layer, namely [Cd(2)(HPO(4))(3)](2-), parallel to the ab plane. The edge-sharing CdO(6) octa-hedra form infinite chains running along the a axis and are linked by CdO(5) and PO(4) polyhedra. The ethyl-ene-diammonium cation and the water mol-ecule are located between two adjacent inorganic layers and ensure the cohesion of the structure via N-H⋯O and O-H⋯O hydrogen bonds.