The World Trade Organization (WTO) members’ have the right to adopt measures and achieve certain non-trade objectives. These objectives, listed as general exceptions, have been a matter in several WTO disputes. One such exception that has found increased use in recent times is the adoption of measures to protect public morals. Public morals were regulated under the General Agreement on Tariffs and Trade (GATT) 1947 to justify any trade restriction in order to protect Members’ interest. Public morals under the WTO are important to research because there is still a lack of definition, research, and understanding among the Members about this topic. There is a significant possibility that contracting parties could use the public morals exception to justify protectionist measures. This research was assessed using the normative legal research that will provide a systematic exposition of the rules governing a particular legal category, analyze the relationship between rules, explain areas of difficulty and, perhaps, predict future development of article XX(a) of GATT 1947 under WTO with the support of four cases that has been settled there are US – Gambling, China Publications and Audiovisual, EC – Seal Products and Columbia – Textiles. After conducting the research, it can be concluded that the compatibility between public morals issue and free trade can be enacted with several requirements both for the WTO and State Members in order to reduce the problem regarding to public morals, and as one of the important exceptions, Members are faced with many conditions and requirements that must be passed to fulfill the intent of the public morals under the WTO. It is suggested the WTO and State Members to work together in order to reduce or even eradicated the problems related to public morals in order to minimize trade barriers and achieve the purpose of the WTO, and Members should not violate their obligations to achieve the purpose of WTO and have to ensure that trade flows as it should be.