The title compound, C(13)H(9)ClN(4)O(3), was synthesized by the condensation reaction of 2-chloro-5-nitro-benzaldehyde with isonicotinohydrazide in a methanol solution. The mol-ecule of the compound displays a trans configuration with respect to the C=N and C-N bonds. The dihedral angle between the benzene and pyridine rings is 12.1 (2)°. In the crystal structure, adjacent mol-ecules are linked through inter-molecular N-H⋯O hydrogen bonds, forming dimers.