Interfacial properties of chiral Schiff bases derived from electron-donating and electron-withdrawing group-substituted salicylaldehyde, respectively, with l-tryptophan, 2-((2-hydroxy-5-methoxybenzylidene)amino)-3-(1H-indol-3-yl)propanoic acid (SB1) and 2-((2-hydroxy-5-nitrobenzylidene)amino)-3-(1H-indol-3-yl)propanoic acid (SB2) on mild steel corrosion in 1 M hydrochloric acid (HCl) solution, were investigated using different techniques like weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy, scanning electron microscopy–energy dispersive X-ray spectroscopy, atomic force microscopy, Fourier transform infrared spectroscopy, UV–visible spectroscopy and X-ray diffraction. All the listed experimental results proved that the corrosion inhibition efficiency of inhibitors mainly depends on its electron-donating ability, as electron-donating group-substituted inhibitor (SB1) has excellent inhibition efficiency on corrosion of mild steel in 1 M HCl compared to electron-withdrawing group-substituted inhibitor (SB2). Density functional theory was further employed to provide insights into the mechanism of interaction between the inhibitor and the mild steel surface. Calculated quantum chemical parameters (E _HOMO, E _LUMO , ΔE, etc.) were act as evident to state that SB1 was better in inhibiting corrosion of mild steel in 1 M HCl compared to SB2.