At the time the EAC was breaking up, a similar organization for West Africa was being created. In May 1975 at a conference in Lagos plans were approved to set up an Economic Community of West African States (ECOWAS). The Treaty establishing ECOWAS was signed at Lome in November 1976 by the heads of alt 15 states of West Africa.

ECOWAS member-states pledged themselves to set up a customs union over 15 years by progressive reduction of import duties. The whole of West Africa will then become a free trade area, with free movement also of people, services and capital. Industrial development will be co-ordinated in order to avoid duplication of resources and capital.

Agricultural policies will be gradually harmonized and joint agricultural projects between member-states will be undertaken, notably in marketing research and food-processing. The first two years of ECOWAS's existence were devoted to setting up administration and gathering information.

The sixteen West African Heads of State signed a revised Treaty on July 24, 1993. The revised Treaty reflects West Africa's regional cooperation experiences over the preceding fifteen years and takes into account the exigencies of continental integration as envisaged in the Treaty of the African Economic Community.

The following 16 member countries make up the Ecowas: Benin, Burkina Faso, Cape Verde, Côte d'Ivoire, The Gambia, Ghana, Guinea, Guinea-Bissau, Liberia, Mali, Mauritania, Niger, Nigeria, Senegal, Sierra Leone, Togo