The non-refoulement principle is nowadays considered to be a fundamental norm of international refugee law. It protects refugees before being expelled to a state in which they might be exposed to persecution. While the customary nature of the non-refoulement principle in international refugee law is unquestionable, opinions on its ius cogens status are not commonly accepted. The emerging of the ius cogens norm requires the fulfillment of a sociological, normative and axiological criteria. At the actual stage of the development of the non-refoulement principle, is not possible to determine whether it acquired ius cogens status, as the above mentioned criteria in the case of non-refoulement have not yet been met together. The views of UNHCR and some doctrinal representatives accepting the imperative nature of non-refoulement should be regarded as voices expressing only a deep concern as regards the need to establish standards of conduct in the field of international refugee law, which would be erga omnes and allowing for effective control of the practices of states and international organizations.