The title compound, C(18)H(18)Cl(2)N(2)O(2), was synthesized by the reaction of 1-(5-chloro-2-methoxy-phen-yl)ethanone with hydrazine hydrate. The mol-ecule lies on a crystallographic twofold axis passing through the mid-point of the N-N bond with one half-mol-ecule in the asymmetric unit. The dihedral angle between the two aromatic rings is 44.33 (4)°. In the crystal, inter-molecular C-H⋯O inter-actions link the mol-ecules into columns along the c axis.