The title compound, C14H11N3O5, is a Schiff base that adopts the enol-imine tautomeric form in the solid state. The dihedral angle between the aromatic rings is 37.4 (3)° and the dihedral angles between the nitro groups and their attached rings are 4.0 (6) and 46.2 (8)°. The mol-ecular structure is stabilized by an intra-molecular O-H⋯N hydrogen bond, which generates an S(6) ring motif. In the crystal, molecules are linked by C-H⋯O interactions, forming a two-dimensional network parallel to the bc plane.