IBBY's biennial congresses bring together IBBY members and other people involved in children's books and reading development from all over the world. The congresses are excellent occasions to make contacts, exchange ideas and open horizons.

Every two years a different National Section hosts the Congress. Several hundred people attend the lectures, panel discussions, seminar sessions and workshops on current congress themes. An IBBY Congress also serves as a frame not only for the General Assembly and other meetings, but also for the presentation of different exhibitions and celebrations such as the Hans Christian Andersen Awards and the IBBY Honour List.