The Inhibition of Aluminum corrosion in 3.5% NaCl solution using diisopropyl thiourea (DISOTU) has been reported by weight loss, electrochemical polarization technique, impedance method and quantum mechanical measurement. It was found that the compound effectively reduces the aluminum corrosion in the sea water medium. It was also noticed that the mere adsorption of the compound on metal surface follows Langmuir adsorption isotherm. The inhibition efficiency (IE) increases as the inhibitor concentration is increased. Quantum mechanical studies confirm the adsorption of protective layer of inhibitor on aluminium surface.