The organically templated vanadium-oxide-organophosphonate phase (C2H5NH3)2[V3O3(H2O)(C6H5-PO3)4] (1) was prepared by the hydrothermal reaction of NH4VO3, C6H5PO3H2, C2H5NH3Cl, NH4Cl, and H2O. The structure consists of alternating inorganic and organic layers, with the organic cationic template occupying tunnels running parallel to the crystallographic a axis. The structure of 1 may thus be described as a hybrid of the layers structures associated with VO(RPO3)(H2O).R’OH phases and the complex framework structures adopted by the analogous phases of the inorganic V/O/PO4(3-) system with organic cations.