The influence of peel of Cucurbita maxima (PCM) on the corrosion inhibition of mild steel in 1N HCl was studied using phytochemical screening, weight loss method, polarization and FTIR studies. The results revealed that PCM was a green corrosion inhibitor of mixed type and electrochemical measurements showed maximum inhibition efficiency (IE) of 85% at and weight loss method shows the maximum IE of 97% at 2% PCM concentration. The inhibitive effect of the plant extract could be attributed to the presence of phytochemical constituents in the plant extract which is adsorbed on the metal surface. The isolated phenols and flavonoids are may be the responsible for the reduction of corrosion rate of mild steel. The EDX results attributed to the adsorption of plant extract onto the metal surface that inhibits the oxidation and corrosion. The system was found to obey El-Awady, Freundlich and Temkin isotherms.