The purpose of this paper is to study by weight loss experiments the effect of 1-vinylimidazole-3-phenacyl hexafluoroantimonate salt (VIPFA) on the corrosion inhibition of mild steel in 1.0 M HCl solution. Weight loss measurements were carried out on mild steel specimens in 1.0 M HCl and in 1.0 M HCl containing various concentrations (5.0·10-4 to 5·10 -7 M) of the laboratory synthesized 1-vinylimidazole-3-phenacyl hexafluoroantimonate salt at temperatures ranging from 303 to 343 K. 1-Vinylimidazole-3-phenacyl hexafluoroantimonate salt (VIPFA) was found to be a very efficient inhibitor for carbon steel in 1.0 M HCl solution, reaching about 92 per cent at the concentration of 5.0·10-4 M at 303 K. The percentage of inhibition in the presence of this inhibitor was decreased with temperature which indicates that physical adsorption was the predominant inhibition mechanism because the quantity of adsorbed inhibitor decreases with increasing temperature. From this study, it was concluded that this inhibitor could have application in industries, where hydrochloric acid solutions at elevated temperatures are used to remove scale and salts from steel surfaces, such as acid cleaning of tankage and pipeline, and may render dismantling unnecessary.