The corrosion inhibition properties of 2-(2-Pyridyl) benzimidazole (PB) for C38 steel in HCl 1M solution were analysed by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization methods. The protection efficiency increases with increasing inhibitor concentration to attain 98.8 % at 2.10-4M. Potentiodynamic polarization data suggests mixed-mode of corrosion inhibition with predominant control of cathodic reaction. The studied inhibitor follows Langmuir adsorption isotherm. Data, obtained from EIS measurements, were analyzed to model the corrosion inhibition process through appropriate equivalent circuit model; a constant phase element (CPE) has been used. The effect of temperature on the corrosion behavior of C38 steel in 1 M HCl, with the addition of PB was also studied and it can be regarded as temperature-independent inhibitor. The activation energy as well as other thermodynamic parameters for the inhibition process was calculated and discussed. The results obtained showed that the PB could serve as an effective inhibitor of the corrosion of C38 steel in hydrochloric acid solution. Quantum chemical parameters were calculated using ab initio and DFT methods to find a good correlation with the inhibition efficiency. A good correlation was found between the theoretical calculations and experimental observations.