The structure of the title compound, C10H11N3OS, comprises an approximately planar mol-ecule, with the r.m.s. deviation for the 15 non-H atoms being 0.089 Å. The conformation about the imine bond is E and an intra-molecular N-H⋯N hydrogen bond is evident. Mol-ecules are linked into a supra-molecular chain along the b axis by N-H⋯S hydrogen bonds.
Keywords: crystal structure; hydrogen bonding; thiosemicarbazone; thiourea.