The title compound, C15H14N2O4 adopts an E conformation about the azomethine double bond. Intra-molecular N-H⋯O and O-H⋯N hydrogen bonds generate S(6) rings and help to establish the molecular conformation. The dihedral angle between the benzene rings is 17.84 (10)°. In the crystal, mol-ecules are linked by O-H⋯O and C-H⋯O hydrogen bonds into a two-dimensional network with a herring-bone pattern arranged parallel to the bc plane.