This study explores the pivotal role of Nigeria in the economic integration and development of West Africa from 1975 to 2023. As the most populous and economically significant nation in the region, Nigeria has been instrumental in shaping the economic landscape of West Africa through its policies, regional cooperation, and development initiatives. Nigeria is the arrowhead of the Economic Community of West African States (ECOWAS) which was formed in 1975, as a regional institution consisting of fifteen nations.

The research investigates Nigeria’s involvement in regional economic integration efforts, such as trade agreements, infrastructural projects, and peacekeeping missions. It evaluates the impact of these contributions on West African economic development. The essence of the establishment of ECOWAS was to promote cooperation and integration in West Africa in order to raise the living standard of its people, to maintain and enhance economic stability, foster relations among members and contribute to the progress and development of the African continent.

This paper argues that while its objectives were initially limited to economic cooperation, emerging political events led to the revision and expansion of ECOWAS’S scope of cooperation to include the maintenance of regional peace, stability and security through promoting and strengthening good neighbourliness. The paper employs power-based and rationalist functionalist approaches in order to elaborate on the big-brother and sub-regional leader role of Nigeria in the West African sub-region and concludes that, in West Africa, regional association has come to be expressed in the formation of ECOWAS in 1975 and the success of which is always hinged on the degree of the determination and commitment of the stronger and Nigeria is manifestly the strongest member.