The crystal and molecular structure of the title compound has been determined by X-ray diffraction methods. It crystallizes in the monoclinic space groupP2₁/n witha=10.072(2),b=19.434(7),c=19.462(3) Å,β=101.07(1)° andZ=4. The anion has a geometry similar to that observed in other related complexes. The two water molecules are hydrogen bonded to each other and are located at van der Waals distances from nitrogen atoms of neighbor nitroprusside anions.