The highest governing authority of ICSU is the General Assembly, made up of National and Scientific Union Members. The General Assembly elects an Executive Board which is responsible for overseeing the operations of the organisation. Policy Committees are established by the General Assembly to assist the Executive Board in fulfilling the governance objectives of ICSU. Ad hoc committees can be established by the Executive Board or the General Assembly to carry out specific functions in a given timeframe.
The global secretariat, located in Paris, manages the day to day operations of the organisation.
ICSU also has three Regional Offices, each with a secretariat hosted by an ICSU National Member. The regional priorities and scientific activities of each office are guided by a regional scientfic committee.
ICSU's European member organizations have a group called The Group of the European members of ICSU. Since 2011 the European Group has had a Secretariat that coordinates and implements the joint activities of the Group.