The inhibiting effect of N-benzylidenebenzohydrazide (BBH) and N′-(3-phenylallylidene) benzohydrazide (PABH) on the corrosion inhibition of mild steel in 1 M HCl solutions were determined by weight loss and electrochemical methods. These inhibitors were adsorbed on the surface according to Langmuir adsorption isotherm. Both BBH and PABH have offered inhibition efficiencies upto 97%. The free energy of activation for the corrosion process has suggested the participation of these molecules in the corrosion process. The adsorbed inhibitor complex has offered barrier protection and prevented the corrosion. The dissolution of iron was also retarded thereby they inhibited corrosion. The surface morphology analysis confirmed the presence of a film on the surface.