A major responsibility of ICMI is to plan for the quadrennial International Congress on Mathematical Education (ICME), held under the auspices of ICMI. This entails, for the ICMI Executive Committee (EC), choosing from among host country bids, appointing an International Programme Committee (IPC) to form the scientific programme and select presenters, and overseeing progress of the congress preparations. The IPC works independently from the Commission. However in order to ensure continuity with general ICMI principles, the ICMI EC normally has representatives on the IPC — in particular the President and Secretary-General of the Commission are ex officio members of the IPC —, one of whom is acting as a liaison officer with the Local Organising Committee of the congress.
The practical and financial organisation of an ICME is the independent responsibility of a Local Organising Committee, again under the observation of general ICMI guidelines. In other words, while it is not ICMI as such which is organizing an ICME, neither in terms of the scientific nor of the practical aspects of the Congress, all ICMEs are held under the Commission's auspices and principles.
Starting with ICME-8, a special ICME Solidarity Fund, built by setting aside some 10% of the total amount collected through the registration fees, has provided grants in order to support and increase participation from less affluent regions of the world to the ICME congresses
Launched in 1969 at the initiative of ICMI President Hans Freudenthal (1905-1990), the ICMEs have been held since then in leap years.