20 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) |  | President Arturo Umberto Illia |  | |
 |  | BOLIVIA | (Sucre + La Paz) |  | Rene Barrientos |  | |
 |  | BRAZIL | (Brasilia) |  | President Humberto de Alencar Castelo Branco |  | |
 |  | CHILE | (Santiago of Chile + Valparaiso) |  | President Eduardo Frei Montalva |  | |
 |  | COLOMBIA | (Bogota) |  | President Guillermo Leon Valencia |  | |
 |  | COSTA RICA | (San Jose) |  | President Francisco Jose Orlich Bolmarich |  | |
 |  | DOMINICAN | (Santo Domingo de Guzman) |  | President Lyndon Baines Johnson |  | |
 |  | ECUADOR | (San Francisco of Quito) |  | Ramon Castro Jijon |  | |
 |  | GUATEMALA | (Guatemala City) |  | Alfredo Peralta Azurdia |  | |
 |  | HONDURAS | (Tegucigalpa + Comayaguela) |  | Oswaldo Lopez Arellano |  | |
 |  | HAITI | (Port Au Prince) |  | President Francois Duvalier Papa Doc |  | |
 |  | MEXICO | (Mexico City) |  | President Gustavo Diaz Ordaz |  | |
 |  | NICARAGUA | (Managua) |  | President Rene Schick 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 |  | |
 |  | AMERICA | (Washington-District of Columbia) |  | President Lyndon Baines Johnson |  | |
 |  | URUGUAY | (Montevideo) |  | President Washington Beltran |  | |
 |  | VENEZUELA | (Caracas) |  | President Raul Leoni |  | |