The asymmetric unit of the title compound, C10H9ClN4S, common name thiacloprid, comprises two molecules. In both molecules, the thiazolidine rings are almost planar (with r.m.s. deviations of 0.016 and 0.065 Å) and form dihedral angles of 73.36 (6) and 70.25 (8)° with the 2-chloropyridine rings. In the crystal, intermolecular C—H...N hydrogen bonds links the molecules into chains propagating in [overline101].