This book chapter analyzes the issue of secession in Bosnia and Herzegovina, with a focus on Republika Srpska. It examines Republika Srpska through a historical, legal, and political lens. Republika Srpska lacks the constitutional right to external self-determination, which includes the right to secede and hold a referendum on its status. However, it has achieved internal self-determination within the framework of the Dayton Peace Agreement and the Constitution of Bosnia and Herzegovina. The tendency towards secession, especially after genocide and other war crimes, is perceived as a threat to the hard-fought Dayton peace. Unilateral secession contradicts the UN Charter and the principles of states’ territorial integrity, sovereignty, and political independence, potentially leading to war. In the case of Bosnia and Herzegovina, it has hindered its path to EU and NATO integration, as well as lasting peace. This chapter concludes that there is general opposition from the international community to unilateral secession.