In modern International Law there is a tension between territorial integrity on the one hand and the right of peoples to self-determination on the other. This study focuses on the territorial integrity of post-colonial states and the national right of self-determination. It also identifies the resulting conflicts and boundary disputes and makes suggestions on how to solve them, taking into consideration recent state practice, as for instance the former Yugoslavia, the former USSR and the former Czechoslovakia, as well as the latest developments in human rights law.