The title compound, C(20)H(22)Cl(2)N(3)O(4)PS, was synthesized by the reaction of N-(4-methoxy-benzyl-idene)-5-(2,4-dichloro-phenyl)-1,3,4-thia-diazol-2-amine and diethyl phosphite. In the crystal, inter-molecular C-H⋯O and N-H⋯O hydrogen bonds link the mol-ecules.