AETOS is a full member of the International Tunnelling Association (ITA), which comprises 78 countries and 266 members, including companies and professionals. The ITA currently has 23 active working groups, 4 standing committees and the Young Tunnellers group, which are responsible for fulfilling the Association's objectives of promoting the development of tunnelling and underground works worldwide.

ITA holds technical meetings through its member organisations all over the world, as well as organising a World Tunnel Congress which coincides with the General Assembly where the main lines of action of the Association are decided.