The corrosion inhibition efficiency of an aqueous extract of Aloe Vera (AV) in controlling the corrosion of carbon steel rain water in absence and presence of with Ni2+ has been studied by weight loss method. Weight loss study reveals that the formulation consisting of 5 ml of AV and 50 ppm of Ni2+ has 98% inhibition efficiency. The results of polarisation study show that the formulation function controls the cathodic reaction predominantly. The AC impedance spectra reveal that a protective film formed on the metal surface. The UV – visible absorption spectra indicates the possibility of formation of Fe2+ -AV complex and also Ni2+ -AV complex in the solution. FTIR spectrum reveal that the protective film consists of Fe2+ -AV complex and Ni(OH)2