This thesis addresses the question as to how the European Union can ensure that EU based MNEs respect human rights when operating in third countries. Firstly, it identifies primary obligations on MNEs as developed by international law in order to tackle the above question. Secondly, on the basis of this theoretical framework it investigates how the European Union has acted to promote respect of human rights obligations by MNEs which are based on the territory of one of its Member States. Thirdly, the gap between the EU’s commitment to the respect and promotion of human rights, the potential to regulate the conduct of MNEs and the EU’s reluctance to impose human rights obligations on MNEs is explored. It is suggested that current human rights law should develop in the sense of considering companies as duty holders, together with States and other non-state actors, for the realisation of human rights. Moreover, a principle of graduation of responsibility is applied to MNEs, according to the specific human right involved, the proximity to the victim and the element of State authority exercised by the company in a particular situation. The above depicted graduation of responsibility (from the obligation to respect, to the obligation to promote human rights) should be matched by a graduation of corresponding implementing mechanisms. Applying this theoretical framework to the EU, three main recommendations have been formulated. Firstly, the EU should more firmly link the promotion of MNEs’ human rights obligations to international human rights law and support the constitution of an international law framework within the UN. Secondly, the EU should promote MNEs’ human rights obligations within the limits of its competence, both at the international and at an external level. It has been argued that a proactive attitude in this respect would not require the acquisition of new powers, but simply the recognition of a functional competence on the basis of Article 6 TEU in taking positive (and not merely negative) steps for the promotion of human rights in the areas of its competence occurring in international law and the international framework for MNEs’ responsibility. Finally, the EU should not abandon the option of exploring non-binding and incentive measures, both at the international and external levels, to be encouraged as a viable complement to binding measures.