This research intends to investigate the scope and applicability of the concept of ‘self-determination’ outside the context of decolonisation using South Sudan as a case study. Demands for the exercise of the right to self-determination are widespread. These are vehemently resisted by states who view the concept of ‘self-determination’ as a potential source of territorial disintegration. International instruments which provide for the right to self-determination also discourage the impairment of the territorial integrity of states in the name of self-determination. The problem faced in international law is therefore how to balance the right to self-determination with the principle of territorial integrity. The study reveals that the general understanding is that outside the context of decolonisation the right to self-determination may be exercised within the territorial boundaries of a state without compromising the territorial integrity of a state. The internal exercise of the right to self-determination entails human rights protection, participation in the political affairs of the state and autonomy arrangements. This general understanding is however problematic where a state systemically violates the rights of its people and denies them political participation in the affairs of the state. The people of South Sudan found themselves in such a situation from the time when Sudan gained independence from British colonial rule. Despite a number of negotiations with the government of Sudan, the people of South Sudan continued to be marginalised and their rights violated with impunity. They then demanded to exercise their right to self-determination externally and eventually they seceded from Sudan through the framework created by the Comprehensive Peace Agreement of 2005. In the light of the secession of South Sudan from Sudan this study proposes a remedial self-determination approach to the understanding of post-colonial self-determination. In terms of this approach when people are denied the right to exercise their right to self-determination internally, or their rights are deliberately and systemically violated, they may exercise their right to self-determination externally and secede.