Corrosion due to carbon dioxide (CO2) is one of the most serious problems in the oil and gas production and transportation industry. The use of corrosion inhibitors is currently used to protect against corrosion in all petrochemical facilities in the world, because it is cost-effective and flexible. The objective of this research is to study the interaction between an imidazoline based inhibitor with an iron carbonate (FeCO3) corrosion product film in controlling the corrosion process and reducing the corrosion rate at various concentrations of inhibitor. CO2 saturated solution of 3 NaCl was used to study the corrosion inhibition of X52 carbon steel samples under stagnant condition at 80°C and pH 6.6. Based on the LPR results, the addition of imidazoline based inhibitor to the test solution decreased the corrosion rate rapidly compared to the iron carbonate film itself. 100 ppm of imidazoline added to the test solution offered a great protection from the corrosion process compared to 50 ppm. Scanning Electron Microscopy (SEM) was used in the analysis of the corrosion samples in order to observe the morphology of films that were formed on the metal surface. It was observed that, the presence of corrosion inhibitor may lead to retard the growth of FeCO3 film and rapidly decrease the corrosion rate. © 2012 University of Manchester and the authors.