In the title compound, C(9)H(9)ClN(2)OS, the 3-chloro-phenyl and acetyl-thio-urea fragments are oriented at a dihedral angle of 62.68 (5)°. An intra-molecular N-H⋯O hydrogen bond generates an S(6) ring motif. Mol-ecules are linked into dimers via a cyclic R(2) (2)(8) motif of N-H⋯S hydrogen bonds. These dimers are further connected through C-H⋯S inter-actions, completing an R(2) (2)(12) motif, into chains along [010].