In the title compound, C(5)H(8)N(6)OS(2), the supramolecular architecture is sustained by two N--H...O and three N--H...S hydrogen bonds, and by N.S electrostatic interactions. The hydrogen-bond network generates a sheet structure, which extends in the a and b directions and is one c-cell dimension thick. These extended sheets are then linked across inversion centres in the c direction by N...S electrostatic interactions, thus forming a three-dimensional network. The principal intermolecular dimensions include N(H)...O distances of 2.8393 (17) and 3.0268 (16) A, N(H)...S distances in the range 3.2896 (14)-3.5924 (16) A and N...S distances of 3.0822 (16) A.