Originally, the Economic and Social Council consisted of 18 members, but the amendments to the charter that came into force on 31 August 1965 raised the number to 27. Another amendment that came into force on 24 September 1973 increased the membership to 54.
When the council was constituted in January 1946, the General Assembly elected the council's first 18 members for staggered terms: 6 members each for one, two, and three years, respectively. Subsequently, all terms were changed to three years, so that each year one-third of the membership is elected by the General Assembly.
The General Assembly resolutions adopting the amendments to the charter that increased the membership of the council also laid down an equitable pattern for the geographical distribution of the additional seats. The 54 members are elected with respect to geographic representation (i.e., to include members from African states, Asian states, Latin American states, Middle Eastern States, and European and other states). Elections are by a two-thirds majority vote on a secret ballot in the General Assembly, and immediate reelection of members is permissible. Although the permanent members of the Security Council have no privileged position on the Economic and Social Council and the charter does not guarantee them membership in the council, it has been the custom to reelect them continuously. In general, the General Assembly has less difficulty in agreeing on its Economic and Social Council selections than in filling Security Council vacancies. Moreover, if, in the opinion of the council, a matter on its agenda is of particular concern to a UN member not represented on the council, it may invite that state to participate in its discussions but without a vote.
In 2002, ECOSOC had the following members: Andorra, Angola, Argentina, Australia, Austria, Bahrain, Benin, Bhutan, Brazil, Burkina Faso, Burundi, Cameroon, Chile, China, Costa Rica, Croatia, Cuba, Egypt, El Salvador, Ethiopia, Fiji, Finland, France, Ghana, Georgia, Germany, Guatemala, Hungary, India, Iran, Italy, Japan, Republic of Korea, Libyan Arab Jamahiriya, Malta, Mexico, Nepal, Netherlands, Nigeria, Pakistan, Peru, Qatar, Romania, Russian Federation, South Africa, Spain, Sudan, Suriname, Sweden, Uganda, Ukraine, United Kingdom, United States, and Zimbabwe.