The corrosion inhibition of iron in 1.0 M HNO3 by some benzimidazole derivatives, namely 2-(aminomethyl)benzimidazole, 2-(chloromethyl)benzimidazole, and 2-(methylthio)benzimidazole has been studied using weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy. The results showed that the inhibition efficiency increased with the increase of benzimidazole derivatives concentration and the higher inhibition efficiency is obtained for 2-(aminomethyl)benzimidazole. Quantum chemical calculations and molecular dynamics (MD) simulations were used to evaluate the structural, electronic, and reactivity parameters of the selected benzimidazole derivatives. The MD method has also been used to simulate the adsorption of the selected benzimidazole derivatives and solvent ions on the iron surface.