Body in White (BIW) is one of the major mass contributors in a full vehicle. Bending stiffness, torsional stiffness, durability, crashworthiness and modal characteristics are the basic performance parameters for which BIW is designed. Usually, to meet these parameters, a great deal of weight is added to BIW. Sensitivity analysis helps to identify the critical panels contributing to the performance while BIW optimization helps to reduce the overall mass of the BIW, without compromising on the basic performances. This paper highlights the optimization study carried out on the BIW of a Sports Utility Vehicle (SUV) for mass reduction. This optimization was carried out considering all the basic performance parameters. In the initial phase of BIW development, optimization helps to ensure minimum BIW weight rather than carrying out mass reduction post vehicle launch.