In the title compound, [Ni(C(6)H(9)N(4)S(2))Cl], the Ni atom is in a slightly distorted square-planar environment coordinated by a Cl atom and a deprotonated thio-semicarbazone ligand via its thia-zoline N, azomethine N and thiol-ate S atoms. Short inter-molecular N-H⋯Cl and C-H⋯S contacts are present in the crystal structure.