In the title compound, C(9)H(17)N(2) (+)·C(17)H(15)N(2)O(2)S(2) (-), the Csp(2)-N bonds in the tetra-hydro-pyrimidine ring of the cation are delocalized. The negative charge is localized on the S atom of the thione group. Cations and anions are linked by N-H⋯S inter-molecular hydrogen bonds.