The surface-mediated synthesis of O-alkyl alkylphosphorohydrazides and N,N-dialkylamino alkylphosphorohydrazides from phosphoryl chlorides is described. The effect of the presence of chromatographic-grade Al2O3(basic) on the hydrazinolysis of a series of O-alkyl alkylphosphonic chlorides and N,N-dialkylamino alkylphosphonic chlorides has also been investigated. It was observed that higher yields of the less-hindered hydrazides were obtained