The significance of an antihistamine drug viz., Cetrizine [CZN] on corrosion of Stainless steel 314 in 2N Sulphuric acid was studies using mass loss measurements, Tafel polarization studies and impedance measurements. The results indicated that CZN is a good inhibitor for SS 314 in 2N H2S04 and maximum efficiency obtained was 94% at 450ppm concentration of CZN. Potentiostatic Polarization analyses showed that CZN acts as a mixed type of inhibitor. Quantum chemical studies were done for Cetrizine and its various quantum chemical parameters were calculated and discussed. © 2017 University of Manchester and the authors.