AbstractThe influence of phenol, p‐cresol, o‐cresol, m‐cresol, pyrogallol, résorcinol and P‐thiocresel on the corrosion of A1 3 S in 0.5 n hydrochlorid acid has been studied; the cathodic behaviour was investigated by a galvanostatic method. The efficiency of the inhibitors depends from the substituents and their position in the ring. It decreases in the order p‐thiocresol — py‐rogallol — resorcinol — phenol—p‐cresol — m‐cresol — o‐cresol. The inhibitors are preferentially adsorbed at the cathodic sites.