Green inhibitors have recently attracted the attention of researchers for their ability to achieve good performance in inhibiting and minimizing corrosion with low environmental impact. For this reason the present study investigates the anticorrosive properties of the extract obtained by macerating the Calamintha nepeta plant leaf powder in favor of carbon steel in 1 M HCl using electrochemical methods, including electrochemical impedance spectroscopy (EIS) and Tafel polarization. The findings indicate that the effectiveness of inhibition increases as the concentration of the inhibitor increases, reaching 96% at 1.5 g/L of the extract; however, the effectiveness decreases with temperature. Polarization curves indicated that the extract functioned as a mixed inhibitor.