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 Juan Carlos Ongania |  | |
 |  | BOLIVIA | (Sucre cj + La Paz eir) |  | President Rene Barrientos | | |
 |  | BRAZIL | (Brasilia) |  | President Humberto de Alencar Castelo Branco | | |
 |  | CHILE | (Santiago of Chile a + Valparaiso l + Vina del Mar s) |  | President Eduardo Frei Montalva | | |
 |  | COLOMBIA | (Bogota) |  | President Carlos Lleras Restrepo | | |
 |  | COSTA RICA | (San Jose) |  | President Jose Joaquin Trejos Fernandez |  | |
 |  | CUBA | (Havana) |  | Supreme Leader Fidel Castro | | |
 |  | DOMINICAN | (Santo Domingo de Guzman) |  | President Joaquin Balaguer | | |
 |  | ECUADOR | (San Francisco of Quito) |  | Otto Arosemena Gomez | | |
 |  | GUATEMALA | (Guatemala City) |  | President Julio Cesar Mendez Montenegro | | |
 |  | HONDURAS | (Tegucigalpa a + Comayaguela c) |  | President Oswaldo Lopez Arellano | | |
 |  | HAITI | (Port Au Prince) |  | Supreme Chief Francois Duvalier Papa Doc | | |
 |  | ITALY | (Rome a) |  | President Giuseppe Saragat |  | |
 |  | MEXICO | (Mexico City) |  | President Gustavo Diaz Ordaz | | |
 |  | NICARAGUA | (Managua) |  | President Lorenzo Guerrero Gutierrez | | |
 |  | PANAMA | (Panama City) |  | President Marco Aurelio Robles | | |
 |  | PERU | (Lima) |  | President Fernando Belaunde Terry | | |
 |  | PARAGUAY | (Assumption) |  | President Alfredo Stroessner | | |
 |  | EL SALVADOR | (San Salvador) |  | President Julio Adalberto Rivera | | |
 |  | URUGUAY | (Montevideo) |  | President Alberto Heber Usher | | |
 |  | VENEZUELA | (Caracas) |  | President Raul Leoni | | |
