Abstract: The invention relates to a method and composition for acidizing a subterranean formation employing an acidic solution comprising hydrochloric acid solution containing a corrosion inhibitor present in a corrosion-reducing effective amount. The corrosion inhibitor comprises the product of the reaction of (i) a compound having at least one reactive hydrogen atom and having no groups reactive under the conditions of reaction other than hydrogen, (ii) a carbonyl compound having at least one hydrogen atom on the carbon atom adjacent to the carbonyl group, (iii) an aldehyde, (iv) a fatty compound and an acid source which is admixed with a source of antimony ions.