In the title compound, C(20)H(15)Cl(2)N(3)O, a typical polysubstituted guanidine with normal geometric parameters, the torsion angles [C-N-C-O = 3.8 (2), N-C-N-C = -6.1 (2)°] indicate that the guanidine and carbonyl groups are almost coplanar, due to the pseudo-hexa-gonal ring formed by intra-molecular N-H⋯O hydrogen bonds. The crystal packing is stabilized by inter-molecular N-H⋯O hydrogen bonds, which link the mol-ecules into centrosymmetric dimers.