Copper corrosion inhibition by Luffa cylinderica leaf extract has been studied in 0.01M Sodium hydroxide solution (NaOH) using electrochemical measurement. Inhibition efficiency increase as the inhibitor concentration increases and decrease with temperature while corrosion rate decreases with concentration and increase with rise in temperature. At the optimum concentration (1000mg/L), the highest inhibition efficiency of plant extract was found to be 72.1846% at 303K and 68.1242% at 313K , and the corrosion rate (10-5) was 1.2679 at 303K and 1.4059 at 313K. However, increase in temperature decreased the inhibition efficiency at the temperature range studied. The phenomenon of physical adsorption has been proposed from the activation energy values (3.8933 to 7.9793 kJ mol-1) with Luffa cylinderica leave extract and the heat of adsorption, Qads ranges from (-26.4619 to - 15.3085 kJmol-1) for concentration of inhibitor studied. These values are negative and suggestive of adsorption on metal surface. The surface morphology and the composition of copper metal were also examined using SEM and XRD analysis respectively. The data obtained from this study fits well into the Langmuir adsorption isotherm.