OSIWA serves the 15 members of the Economic Community of West African States (ECOWAS), as well as Cameroon, Chad and Mauritania..
Benin - Burkina Faso - Cameroon - Cape Verde - Chad - Côte d’Ivoire - Gambia - Ghana - Guinea - Guinea-Bissau - Liberia - Mali – Mauritania- Niger - Nigeria - Senegal - Sierra Leone - Togo.

