The effect of some benzaldehyde derivatives on the corrosion of zinc in 0.5 M HCl solution is studied in this article using mass loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) techniques. The percentage inhibition efficiency (%In) was found to increase with increasing concentration of the inhibitor and with decreasing temperature. Polarization studies indicated that all of the compounds studied are mixed-type inhibitors. The inhibitive action of these benzaldehyde derivatives has been discussed in view of the adsorption on the zinc surface. The adsorption process follows Temkins isotherm. The addition of KSCN, KI, and KBr to benzaldehyde derivatives has enhanced the inhibition efficiency because of synergistic effect. The mechanism of inhibition process is discussed in the light of the chemical structures of the investigated inhibitors.