The General Assembly is the controlling and electing body of the Union and represents all adhering bodies of the Union.
- It elects officers of the Union, as well as its executive committee, the Council. It decides on all changes in the statutes and ratifies changes in the Constitution and By-Laws and in membership where necessary. It shall be guided in all its decisions by the tradition of free international cooperation (Article 4.1 of the IUIS Constitution).
- The General Assembly shall consist of the officers of the Union and of delegates appointed by the Regular Members, Regional Federations and International Affiliate Members, and the Standing Committees (Article 4.2 of the IUIS Constitution).
- Delegates to the General Assembly serve from the beginning of one General Assembly meeting until the end of the period before the next meeting. General Assembly meetings will normally be held at the International Congress of Immunology (Article 4.3 of the IUIS Constitution).