AbstractCorrosion of carbon steel rebars is the main cause of failure of reinforced concrete structures. To prevent and delay the occurrence of corrosion, a high quality concrete with a proper cover and a good mixture proportion should be designed. Additional prevention methods are used if severe environmental conditions occur, or when structures require very long service life. Corrosion inhibitors seem to be attractive because of their low cost and easy handling, compared to other preventive methods. This paper analyses results of a 10‐year investigation on the effectiveness of four commercial inhibitors and two pure organic compounds in preventing chloride‐induced corrosion. Tested inhibitors seem to be able to increase time‐to‐corrosion: their effects on chloride penetration rate and on critical chloride threshold are discussed.