5-Hy-droxy-2-nitro-benzaldehyde thio-semicarbazone (HNBATSC).

The asymmetric unit of the title compound, C8H8N4O3S, consists of two independent mol-ecules. Each mol-ecule is approximately planar with dihedral angles of 8.71 (3) and 1.50 (2)° between the aromatic ring and the thio-semicarbazide moiety while the NO2 group makes dihedral angles of 29.27 (3) and 17.78 (3)° with the benzene ring. In the crystal, the molecules are linked by N-H⋯S, O-H⋯O and N-H⋯O hydrogen bonds, forming two-dimensional networks parallel to (100).