The corrosion of aluminium in trichloroacetic acid (TCA) containing xylenol orange has been studied. In TCA, the corrosion rate increases with the increase in acid concentration. At constant acid concentration, the inhibition efficiency of xylenol orange increases with the inhibitor concentration. At constant inhibitor concentration, the inhibition efficiency decreases with the increase in the acid concentration. As temperature increases, percentage of inhibition decreases. Plot of log (theta/1-theta) versus log C results in a straight line, suggesting that the inhibitor cover both the anodic and cathodic regions through general adsorption following Langmuir isotherm. The polarization curves show very little anodic but significant cathodic polarization.