The active components in tomato peels were extracted using alcohol, and FTIR was measured to clarify the structure. Electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PP), and weight loss (WL) measurements were used to investigate the corrosion inhibition of carbon steel in acetic acid solution. The corrosion rate decreased as the extract content increased. Additionally explained were the rise in charge transfer resistance and the fall in polarization current densities; an indication for the inhibitory effect. The findings demonstrated that the inhibitory effect was caused by the physical adsorption of molecules on the carbon steel surface majorly at the cathodic locations, forming a barrier that protected the steel from the corrosive medium. This adsorption followed Langmuir isotherm. Also, the temperature effect showed a tendency of tomato peels extract to inhibit the corrosion, cathodically.