Atmospheric corrosion rate of Al, Zn and mild steel (MS) as well as salinity and sulphation rate have been determined under outdoor exposure at Tithal (Dist. Valsad) situated in South Gujarat, India. MS samples exposed vertically suffer less corrosion than those exposed at an angle of 45°. Monthly corrosion rate was in the decreasing order of Al <Zn <Ms; whereas yearly rate also follow the same trend.