21 Members (excluding the associate or suspended members but including the countries represented on their behalf) [The rulers are not necessarily the representatives in the organisation. ] :
 |  | ARGENTINE | (Buenos Aires a + Olivos r) |  | President Pedro Eugenio Aramburu |  | |
 |  | BOLIVIA | (Sucre cj + La Paz eir) |  | President Hernan Siles Zuazo | | |
 |  | BRAZIL | (Rio de Janeiro) |  | President Juscelino Kubitschek | | |
 |  | CHILE | (Santiago of Chile a + Valparaiso l + Vina del Mar s) |  | President Carlos Ibanez del Campo | | |
 |  | COLOMBIA | (Bogota) |  | President Gustavo Rojas Pinilla | | |
 |  | COSTA RICA | (San Jose) |  | President Jose Figueres Ferrer |  | |
 |  | CUBA | (Havana) |  | President Fulgencio Batista | | |
 |  | DOMINICAN | (Ciudad Trujillo) |  | Generalissimo Rafael Leonidas Trujillo | | |
 |  | ECUADOR | (San Francisco of Quito) |  | President Camilo Ponce Enriquez | | |
 |  | GUATEMALA | (Guatemala City) |  | Carlos Castillo Armas | | |
 |  | HONDURAS | (Tegucigalpa a + Comayaguela c) |  | Military Council of Government | | |
 |  | HAITI | (Port Au Prince) |  | Joseph Nemours Pierre-Louis | | |
 |  | MEXICO | (Mexico City) |  | President Adolfo Ruiz Cortines | | |
 |  | NICARAGUA | (Managua) |  | President Luis Somoza Debayle | | |
 |  | PANAMA | (Panama City) |  | President Ernesto de la Guardia | | |
 |  | PERU | (Lima) |  | President Manuel Prado Ugarteche | | |
 |  | PARAGUAY | (Assumption) |  | President Alfredo Stroessner | | |
 |  | EL SALVADOR | (San Salvador) |  | President Jose Maria Lemus | | |
 |  | AMERICA | (Washington-District of Columbia) |  | President Dwight David Eisenhower | | |
 |  | URUGUAY | (Montevideo) |  | President Alberto Fermin Zubiria | | |
 |  | VENEZUELA | (Caracas) |  | President Marcos Perez Jimenez | | |
