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 Isabel Peron | | |
| | BOLIVIA | (Sucre cj + La Paz eir) | | President Hugo Banzer | | |
| | BRAZIL | (Brasilia) | | President Ernesto Geisel | | |
| | CHILE | (Santiago of Chile a + Vina del Mar s) | | General Augusto Pinochet | | |
| | COLOMBIA | (Bogota) | | President Misael Pastrana Borrero | | |
| | COSTA RICA | (San Jose) | | President Daniel Oduber Quiros | | |
| | CUBA | (Havana) | | Supreme Leader Fidel Castro | | |
| | DOMINICAN | (Santo Domingo de Guzman) | | President Joaquin Balaguer | | |
| | ECUADOR | (San Francisco of Quito) | | President General Guillermo Rodriguez Lara | | |
| | GUATEMALA | (Guatemala City) | | President Kjell Eugenio Laugerud Garcia | | |
| | HONDURAS | (Tegucigalpa a + Comayaguela c) | | Oswaldo Lopez Arellano | | |
| | HAITI | (Port Au Prince) | | President Jean-Claude Duvalier Baby Doc | | |
| | ITALY | (Rome a) | | President Giovanni Leone | | |
| | MEXICO | (Mexico City) | | President Luis Echeverria Alvarez | | |
| | NICARAGUA | (Managua) | | National Government Junta | | |
| | PANAMA | (Panama City) | | Supreme Leader General Omar Torrijos Herrera | | |
| | PERU | (Lima) | | President Juan Velasco Alvarado | | |
| | PARAGUAY | (Assumption) | | President Alfredo Stroessner | | |
| | EL SALVADOR | (San Salvador) | | President Arturo Armando Molina | | |
| | URUGUAY | (Montevideo) | | President Juan Maria Bordaberry | | |
| | VENEZUELA | (Caracas) | | President Carlos Andres Perez | | |