TEPSA is a decentralised think tank that consists of members and affiliated members. Established in 1974 by five institutes, TEPSA has ever since increased its membership to include institutes all throughout Europe as a reaction to the enlargement rounds of the European Union. The members of TEPSA are leading national think tanks or research institutes in the field of European affairs. The network includes in principle only one member in each of the European’s Union member states. Next to this membership, TEPSA also has affiliated members. Affiliated members are research institutes or associations focused on European affairs but not directly linked to an EU member state, either as a result of their transnational nature or because they are established in a state associated with the European Union like an EU candidate country.

TEPSA currently consists of 33 member institutes and associate members located in 29 countries, both EU member states and candidate countries. TEPSA continues to expand its membership via a careful selection procedure. The TEPSA Board is the main organ in charge of the selection process, while it is the TEPSA General Assembly that hold the final decision-making powers. Institutes or associations interested in TEPSA membership or affiliated membership can contact the TEPSA Secretariat for more information.