Two new layered vanadium phosphates templated by ethylenediamine, (NH3CH2CH2NH3)(1.5)[(VO)(2)(HPO4)(2)(PO4)] (1), and piperazine, (C4H12N2)(2)[V4O6H(HPO4)(2)(PO4)(2)] (2), have been synthesized hydrothermally and their structures determined by single-crys