The title compound, triammonium cis-diaqua-cis-dioxo-trans-disulfatovanadate 1.5-hydrate, was obtained by oxidizing V(IV) to V(V) in a 2 M sulfuric acid solution of vanadyl sulfate and adding ammonium sulfate. Here, the V atom is sandwiched by two sulfate groups by corner-sharing to form a discrete [VO(2)(SO(4))(2)(OH(2))(2)](3-) anion. The water molecules occupy cis positions in the equatorial plane of the vanadium octahedron.