In this short communication we provide a glimpse into the unexpected, intriguing nature of 2,4- hexadienoic acid potassium salt {potassium sorbate [K(CH3CH=CHCH=CHCO2)]}, namely, its high superiority over other corrosion inhibitors to protect metals and alloys (copper, carbon steel, aluminum, and stainless steel) from surface degradation processes in a wide range of potentials in the presence of corrosive environments. (c) 2005 The Electrochemical Society.