Original 51 Members (1945)
Argentina, Australia, Belgium, Bolivia, Brazil, Byelorussian Soviet Socialist Republic, Canada, Chile, China, Colombia, Costa Rica, Cuba, Czechoslovakia, Denmark, Dominican Republic, Ecuador, Egypt, El Salvador, Ethiopia, France, Greece, Guatemala, Haiti, Honduras, India, Iran, Iraq, Lebanon, Liberia, Luxembourg, Mexico, Netherlands, New Zealand, Nicaragua, Norway, Panama, Paraguay, Peru, Philippine Republic, Poland, Saudi Arabia, Syria, Turkey, Ukrainian Soviet Socialist Republic, Union of South Africa, Union of Soviet Socialist Republics, United Kingdom, United States, Uruguay, Venezuela, Yugoslavia
55 Members (1946)
Added: Afghanistan, Iceland, Siam, Sweden
57 Members (1947)
Added: Pakistan, Yemen
58 Members (1948)
Added: Burma
59 Members (1949)
Added: Israel
60 Members (1950)
Added: Indonesia
76 Members (1955)
Added: Albania, Austria, Bulgaria, Cambodia, Ceylon, Finland, Hungary, Ireland, Italy, Jordan, Laos, Libya, Nepal, Portugal, Romania, Spain
80 Members (1956)
Added: Japan, Morocco, Sudan, Tunisia
82 Members (1957)
Added: Ghana, Federation of Malaya
82 Members (1958)
Added: Guinea
99 Members (1960)
Added: Cameroun, Central African Republic, Chad, Congo (Brazzaville), Congo (Leopoldville), Cyprus, Dahomey, Gabon, Ivory Coast, Malagasy Republic, Mali, Niger, Nigeria, Senegal, Somalia, Togo, Upper Volta
104 Members (1961)
Added: Mauritania, Mongolia, Sierra Leone, Tanganyika
110 Members (1962)
Added: Algeria, Burundi, Jamaica, Rwanda, Trinidad and Tobago, Uganda
113 Members (1963)
Added: Kenya, Kuwait, Zanzibar
115 Members (1964)
Added: Malawi, Malta, Zambia
117 Members (1965)
Added: The Gambia, Maldive Islands, Singapore
122 Members (1966)
Added: Barbados, Botswana, Guyana, Lesotho
123 Members (1967)
Added: Yemen
126 Members (1968)
Added: Equatorial Guinea, Mauritius, Swaziland
127 Members (1970)
Added: Fiji
132 Members (1971)
Added: Bahrain, Bhutan, Oman, Qatar, United Arab Emirates
135 Members (1973)
Added: Bahamas, Federal Republic of Germany, German Democratic Republic
138 Members (1974)
Added: Bangladesh, Grenada, Guinea-Bissau
144 Members (1975)
Added: Cape Verde, Comoros, Mozambique, Papua New Guinea, Sao Tome and Principe, Suriname
147 Members (1976)
Added: Angola, Samoa, Seychelles
149 Members (1977)
Added: Djibouti, Viet Nam
151 Members (1978)
Added: Dominica, Solomon Islands
152 Members (1979)
Added: Saint Lucia
154 Members (1980)
Added: Saint Vincent and the Grenadines, Zimbabwe
157 Members (1981)
Added: Antigua and Barbuda, Belize, Vanuatu
158 Members (1983)
Added: Saint Christopher and Nevis
159 Members (1984)
Added: Brunei Darussalam
159 Members (1990)
Added: Liechtenstein, Namibia
166 Members (1991)
Added: Democratic People's Republic of Korea, Estonia, Latvia, Lithuania, Marshall Islands, Federated States of Micronesia, Republic of Korea
179 Members (1992)
Added: Armenia, Azerbaijan, Bosnia and Herzegovina, Croatia, Georgia, Kazakhstan, Kyrgyzstan, Republic of Moldova, San Marino, Slovenia, Tajikistan, Turkmenistan, Uzbekistan
184 Members (1993)
Added: Andorra, Czech Republic, Eritrea, Monaco, Slovakia, The former Yugoslav Republic of Macedonia
185 Members (1994)
Added: Palau
188 Members (1999)
Added: Kiribati, Nauru, Tonga
189 Members (2000)
Added: Federal Republic of Yugoslavia, Tuvalu
191 Members (2002)
Added: Switzerland, Timor-Leste
192 Members (2006)
Added: Montenegro
193 Members (2011)
Added: South Sudan