This study is mainly conducted for providing detailed information on protecting the investors and their foreign direct investment under WTO regime. Moreover, the study going to develop the role of foreign investment in enhancing national economic growth while critically examining foreign investment as a way of assessing its impact and effectiveness in Saudi Arabia. While evaluating this topic area, various important aspects in relation with WTO and TRIMs agreement are also explored. Along with this, this study also explores the impact and effectiveness of foreign investments in terms of the growth of Saudi economy and trade market. This study is also set for examining the role of WTO in attracting FDIs to Saudi Arabia. In addition this study is also helpful in evaluating the legal mechanisms under WTO in order to control fraud and protect investments.