The inhibitive action of the Juniper Oxycedrus Extract (JOE) against corrosion of carbon steel in a 1.0 M HCl solution was investigated using electrochemical impedance spectroscopy, potentiodynamic polarization curves and weight loss measurements. The results indicate that the extracts functioned as a good inhibitor in acidic medium environments and inhibition efficiency increased with extracts concentration. Temperature studies revealed an increase in inhibition efficiency with rise in temperature and activation energies decreased in the presence of the extract. Polarization curves show that JOE behaves as a mixed-type inhibitor in hydrochloric acid. EIS shows that charge-transfer resistance increase and the capacitance of double layer decreases with the inhibitor concentration, confirming the adsorption process mechanism. The adsorption of Juniper Oxycedrus Extract on the surface of the carbon steel follows the Langmuir adsorption isotherm.