This Paper intends to give an overview of the development in the concept of self-determination made by United Nations after World War II, from the last period of colonialism, codifying the right to self-determination and considering the Peoples who suffered from it as subjects of this right, until the appearance of secessionist episodes and the restricted reformulation on the following decades; then, the assumption of the theory of secession-remedy will be scrutinized as the last step in the evolution of self-determination in response to episodes of grave violations of human rights and restrictions of self-government faculties.