The purpose of this study is to examine the role of Nigeria in the formation of regional organization (ECOWAS) considering the need for West Africa to have a regional organization with common goals and the formative years of ECOWAS. This research also examine the Nigeria’s interest in ECOWAS and the successes/challenges of the regional organization. Data was obtained from the secondary sources like Journals, textbooks, internet and all other secondary sources. More data were also gathered through interviews. The data obtained was analyzed using thematic format and a descriptive essay and the result revealed that Nigeria played a major role in the formation of ECOWAS because their special interest is in regional and borderless organization uniting the West African countries to improve trade and transportation with an introduction of common currency. Nigeria has played a leading role in funding the organization. However, the organization has not been able to achieve many of the goals in the mission system due to several challenges and the non supportive nature of some member countries. This study concludes that Nigeria should continue playing the big brother role to ensure the success of the regional organization. It however recommends that other west African countries should come together in cooperation to ensure the success of the organization.