In the title compound, C(18)H(18)ClN(5)O(3), the hydrazinecarboxamide N-N-C(O)-N unit is nearly planar [maximum deviation = 0.074 (2) Å] and is inclined at a dihedral angle of 57.43 (7)° with respect to the plane of the attached benzene ring. The chloro-phenyl group makes dihedral angles of 19.71 (7) and 34.07 (6)° with the pyrazole and benzene rings, respectively. In the crystal, pairs of N-H⋯O hydrogen bonds link the mol-ecules into inversion dimers that are further linked into chains along the a-axis direction by N-H⋯N hydrogen bonds. In addition, π-π stacking inter-actions are observed between benzene rings [centroid-centroid distance = 3.680 (1) Å].