The asymmetric unit of the title compound, [U(C(5)H(7)O(2))(2)O(2)(H(2)O)]·C(4)H(4)N(2), contains one [UO(2)(acac)(2)(H(2)O)] (where acac is acetyl-acetonate) and two half-mol-ecules of pyrazine. It exhibits a UO(7) penta-gonal-bipyramidal coordination geometry about the U(VI) atom, involving two bidentate acetyl-acetonate ions and one water mol-ecule. The N atoms of the pyrazine mol-ecules are not coordinated to the U(VI) atom, and are connected with the aqua O atom by hydrogen bonds. This results in a zigzag chain arrangement along the [10] direction.