In the title compound, C(9)H(10)N(2)O(3), the Schiff base mol-ecule is approximately planar, the dihedral angle between the benzene ring and the acetohydrazide group (r.m.s. deviation = 0.034 Å) being 8.81 (7)°. An intra-molecular O-H⋯O hydrogen bond is observed. In the crystal, mol-ecules are linked into a three-dimensional network by O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds.