There are 183 states currently engaged in diplomatic relations with the Holy See. The European Union and the Sovereign Military Order of Malta are to be added to the aforementioned states.

There are 89 Embassy Chancelleries based in Rome, including those of the European Union and the Sovereign Military Order of Malta. The offices of the League of Arab States, the International Organization for Migrations and the United Nations High Commissioner for Refugees are also based in Rome.

During 2018, on 26 June, an Agreement between the Holy See and the Republic of San Marino was signed for the teaching of the Catholic religion in public schools, ratified the following 1 October. On 23 August 2018 the Framework Agreement between the Holy See and the Republic of Benin on the legal status of the Catholic Church in Benin was ratified. On 22 September 2018 a Provisional Agreement was signed by the Holy See and the People’s Republic of China on the appointment of bishops in China. In addition, on 16 July the Holy See deposited the instruments of ratification of the UNESCO Regional Convention on the recognition of higher teaching qualifications in Asia and the Pacific, and on 21 March 2018 it signed the enlarged Partial Agreement on Cultural Routes of the Council of Europe. On 30 November 2018, Vatican City State was admitted to the Single Euro Payments Area (SEPA).