In this research, the author pays attention to one of the most topical problems of international law: the recognition by the United Nations international and regional organizations, in particular the Arab League. The sources analyzed are the official documentation of the UN and the League as well as the analytical literature on international law. This article presents a detailed analysis of the relationship between the two organizations during the period between 1945 and 1960, i.e. before the adoption of the Memorandum of Understanding on Cooperation between the two Secretariats. The Arab league is shown in the article as the oldest international regional organization. The author is convinced that there is no provision on supra state organizations in the UN Charter and seeks to reveal the consequences of this situation. He states that the lack of the criteria, forms and ways in the charter, which would make recognizing such organizations in the future possible. The author focuses on the questions of the strategy of the de jure recognition of the League by all the UN bodies. The article stresses that the League seeking international recognition followed the pattern of the Organization of American States which was established later. The author notes that the League has established formal relations with the UN and its special bodies since the 1950s. In the UNGA, the League is vested with a status of the observer. However, as the author reminds, the league has not been recognized formally as an international regional organization until now. The reason is seen in the fact that the UN is an organization of sovereign states, hence supra state organizations can not join it as fully-fledged members.