The Republic of Estonia celebrates its 95th anniversary on February 24, 2013. Although teachers had aspired for their own organization in the middle of the 19th century, the idea could not be implemented on historical reasons before. The first teachers’ societies were organised in different regions of the country in April- May 1917.Teachers of Tartu and Tallinn were convinced of the need to establish an organization uniting teachers all over the country and these activities peaked with establishment of Estonian Teachers’ Union in the spring of 1917 (in 1917-1919 it was called Estonian Central Union of School Teachers). Estonian Teachers’ Union (ETU) was from the beginning of its existence well known for its activities developing national schools, modernising education and establishing international contacts in the pre-WWII period in Estonia (1918-1940). ETU was for the Ministry of Education a valuable partner in developing educational legislation and solving problems of school practice. At the same time the union defended its members’ professional and economic interests. Contribution made by ETU to organization and management of Estonian education and cultural developments at large is a heritage we could learn from today. Its high organizational culture, wide variety of activities and remarkable personalities as its leaders deserve particular attention. Materials related to ETU are preserved at the Estonian Pedagogical Archives-Museum containing manuscripts (written by leaders of ETU), publications (incl. pedagogical journal Kasvatus/Education of 1919- 1940) and photos. This presentation is focused on the role of ETU as a representative body in the process of developing national schools, educational innovation and international contacts between 1917 – 1940.