The paper is focused on international aspects of the Long-Term Ecological Research (LTER). It provides information on history of the LTER programme from its establishment in USA in 1980 through gradual development of international collaboration to recent activities, both in global and European levels. The role and involvement of Slovak scientists in the international cooperation is specifid as well. During the last years the global network ILTER have focused especially on the thematic initiatives aiming at involvement of the international LTER community to study of specifif issues, on educational activities, especially for the new generation of LTER scientists and on its fist conference organized in 2016 – The Open Science Meeting in South Africa. The regional network LTER-Europe is gradually building its capacities, harmonising methods and fostering international cooperation especially through several consecutive projects, namely ALTER-Net (2004–2009), EnvEurope (2010–2013) and eLTER (2015–2019).