The asymmetric unit of the title compound, C(7)H(6)ClN(3)S, consists of two crystallographically independent mol-ecules (A and B). The dihedral angle between the benzothia-zole ring system and the hydrazine group is 8.71 (6)° in mol-ecule A and 7.16 (6)° in mol-ecule B. The N-N-C-N and N-N-C-S torsion angles involving the hydrazine group are 170.89 (9) and -9.96 (13)°, respectively, in mol-ecule A and 172.50 (9) and -7.43 (13)°, respectively, in mol-ecule B. In the crystal, neighbouring mol-ecules are connected via pairs of N-H⋯N hydrogen bonds, generating R(2) (2)(8) ring motifs, and are connected further by N-H⋯N hydrogen bonds into sheets lying parallel to the ab plane. The crystal studied was an inversion twin, the refined ratio of the twin components being 0.50 (3):0.50 (3).