Estonia became a member of the United Nations on 17 September 1991. Estonia’s first Permanent Representative to the UN headquarters was Ernst Jaakson, Estonia’s long time Consul General in New York and Head of Mission in the United States, a diplomat who with his service helped to maintain the legal continuity of the Republic of Estonia through the Soviet occupation.
Out of the 5 UN’s regional groups (Asian, African, Latin-American and Caribbean, Eastern European, Western European and Others) Estonia has been a member of the Eastern European Group since May 2004.
You can find more detailed information about the activities of Estonia in UN on the website of Ministry of Foreign Affairs of Estonia.