The corrosion inhibition of 2-(benzylthio)-1,4,5-triphenyl-1H-imidazole (BTI) for carbon steel in a 1 M HCl solution was studied by means of weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM) methods. Quantum chemical calculations based on the DFT method were performed on BTI. Molecular dynamics simulations were carried out to establish the mechanism of corrosion inhibition for carbon steel with BTI in HCl. Kinetic and thermodynamic parameters of activation using a statistical model were calculated. Polarization curves revealed that BTI is a mixed-type inhibitor. The results showed that BTI is a good inhibitor for the corrosion of carbon steel in 1.0 M HCl solution and that its inhibition efficiency is higher than 88% at 1 x 10(-3) M BTI. Adsorption of the inhibitor on the carbon steel surface follows the Langmuir adsorption isotherm, and the value of the free energy of adsorption, A Gad,, indicates that the adsorption of BTI is a spontaneous process.