In this work, the electrochemical reduction of some Schiff’s bases contains substituted coumarin moiety and the effects of the substituents have been studied by polarographic technique. Based on the results obtained and previous literature, a tentative mechanism has been proposed. The system investigated in this study was a series of substituted (17Z)-2-(4-methyl-2-oxo-2H-chromen-7-yloxy)-N'-benzylideneacetohydrazides. The system possesses two electrophores; (1) Hydrazone group and (2) Carbonyl group. Thus, the electrochemical reduction of the system, studied with DC polarography, might provide valuable insight into the processes taking place on the surface of the electrode and can be of importance in fundamental electrochemical research.