In recent years, the implementation of and compliance with general values such as the protection of human rights, labor, environment, and democracy has become a very important agenda in global trade policy. The new Secretary General of the WTO emphasized her strong interest in the WTO negotiations in reforming various subsidies for fishing industries, which are to be concluded by the upcoming Twelfth MC (Ministerial Conference) in November 2021. Sustainability has become another critical issue in the international trade context. Plurilateral initiatives among 50 WTO member countries have already been taken regarding the Structured Discussion on Trade and Environmental Sustainability (SDTES). In these circumstances, this study on the EU’s IUU case toward Thailand helped to understand how Thailand’s compliance with the EU IUU Regulation has affected Thailand in achieving the goal of “sustainability” of both fishing practice and working conditions in its fishing industry. The EU’s imposition of the “Status of IUU Nations Carded“ has created the grounds to combat IUU fishing in Thailand by converting an issue of public interest into a private sector issue, for which the sharp decline in fish exports is a matter of concern. This EU–Thailand case also indicated that along with intensifying international cooperation and surveillance for improving the working environment, the inclusion of a human rights issue as a tool for correcting trade distortion is most urgent and essential. For the sustainability of both economic and societal values of developing countries such as Thailand, a firm and solid implementation of adequate working conditions should be employed among global trade participants.