This article observes the features of the formation of foreign policy institutions of the Nagorno-Karabakh Republic (NKR) and the development of its international relations. The main stages of the NKR foreign policy priorities are analyzed and the role of the Armenian Diaspora in lobbying the interests of Karabakh in the international arena is examined. The first attempt in Russian historiography is made to investigate the foreign policy resource base of the unrecognized republic. The basic sources of research are materials from the official website of the Ministry of Foreign Affairs of the NKR, the OSCE documents on the Nagorno-Karabakh conflict, as well as information posted on the websites of the Nagorno-Karabakh representation in the United States and France. The main subject of the research is to identify the key features of the NKR foreign relations since the establishment of the Ministry of Foreign Affairs of the unrecognized republic until the present day. The article presents two main conclusions. Firstly, the main state institution dealing with foreign policy activities is the Ministry of Foreign Affairs of the NKR, it operates in two main areas: the settlement of the conflict and the international recognition of Nagorno-Karabakh. In addition, the NKR has seven foreign permanent missions, functioning as embassies and consulates. In spite of its unrecognized status, Nagorno-Karabakh has offices, including in the US, Russia and France. Secondly, the research notes that the important foreign policy resource of Nagorno-Karabakh is a large Armenian Diaspora, represented by such influential organizations as the Armenian National Committee of America (ANCA), Armenian Assembly of America (AAA), the Coordination Council of Armenian Organizations of France (CCAF) and others. Nagorno-Karabakh is able to lobby its national interests in different states through such organizations. The Armenian lobby makes its significant contribution to the international recognition of the NKR; moreover, with the help of the lobby, the unrecognized republic has an opportunity to enter the international arena. In addition, there is a number of Diaspora funds engaged in the realization of infrastructure projects in the Nagorno-Karabakh Republic.