The ITI organises its World Congress in collaboration with a national centre and a selected city, bringing together representatives of ITI centres from all continents.

In addition to the statutory section (the general assembly, committee meetings, networks, forums and project groups), each ITI World Congress has an artistic programme section with performances (local and international, international cooperation projects), an educational section (workshops, seminars, conferences) and special thematic events on global civil society and cultural policy issues. 

The founding congress of the International Theatre Institute took place in Prague in 1948. The World Congress was initially held annually, then every two years, and since 2011 every three years.

To date, there have been 35 World Congresses, 26 of which were held in Europe (including West Berlin in 1975, East Berlin in 1983, and Munich in 1983), four in the Asia-Pacific region, and five in the Americas.