A novel 2,6-diaminopyridine vanadate hydrate C20H38N12O15V4 has been synthesized from hydrothermal reaction and the crystal structure has been determined by means of single-crystal X-ray diffraction. Triclinic, P-1. a=7.9516(6) Å, b =10.2810(10) Å, c =11.7780(11) Å, α= 74.590(3)° , β=72.500(3)° , γ=89.151(5)° . V=883.06(14). Z=1. R1 =0.0424, wR2 =0.1378, T=291(2) K. The V atom is four coordinated by four O atoms. The crystal packing is stabilized by O-H...O and O-H...N hydrogen bonding interactions.