The Sudan Interior Mission/Evangelical Church Winning All (SIM/ECWA) was one of the mission agencies that brought Christianity to Nigeria.The Mission was introduced to IÌ€gboÌmiÌ€naÌ€ land, Kwara State, in 1912. Prior to the coming of SIM/ECWA, into the land, significant development was a mirage. The aim of this study was to document the impacts of this mission in IÌ€gboÌmiÌ€naÌ€ land, Kwara State, Nigeria. The objectives of this study were to: (i) examine how SIM/ECWA penetrated IÌ€gboÌmiÌ€naÌ€ land; (ii) investigate the level of development of the mission in IÌ€gboÌmiÌ€naÌ€ land over the period of one hundred years (1912-2012); (iii) document the various impacts of the mission onIÌ€gboÌmiÌ€naÌ€ land; (iv) appraise the contributions of Nigerian converts to the spread of SIM/ECWA in IÌ€gboÌmiÌ€naÌ€ land; (v) examine the ability of ECWA to sustain the legacy passed to her by SIM; and (vi) assess the impact of SIM/ECWA as an agent of socio-economic transformation of IÌ€gboÌmiÌ€naÌ€ land.rnrnThis study employed qualitative research design using the historical method. Historical method was used to trace the history of the development of SIM/ECWA in IÌ€gboÌmiÌ€naÌ€ land and to give a vivid description of the various means through which the Church penetrated the towns and villages in the area. A total of thirty-two people including clergymen, elders, chiefs and members of SIM/ECWA who were indigenes and non-indigenes of IÌ€gboÌmiÌ€naÌ€ land were purposely selected for interview. Participant observations were also used for eliciting information. rnrnThe findings of this study were that: rn(i) SIM/ECWA came into IÌ€gboÌmiÌ€naÌ€ land through OÌ€roÌ€-AÌ€gá»Ì in 1912 via Rev. GuyWilliam Playfair and penetrated other towns and villages in the land through house to house preaching, friendship with traditional rulers and healing strategies; rn(ii) SIM/ECWA that started with only one mission station and one local church in 1912 had spread widely with five mission stations, three District Church Councils and over one hundred Local Church Boards all over IÌ€gboÌmiÌ€naÌ€ land;rn(iii) SIM/ECWA had tremendous impacts on IÌ€gboÌmiÌ€naÌ€ land in the areas of education, economy, social, medical, etc;rn(iv) Nigerian converts like ÃŒjẹ̀sà cloth traders (ÒṣoÌmaÌ€aÌloÌ), and persons like Jamu Adeniyi, Abraham Buremoh, and many more had contributed greatly to the spread of SIM/ECWA in IÌ€gboÌmiÌ€naÌ€ land by establishing SIM/ECWA Local Church Boards; rn(v) ECWA has not been able to sustain all the legacies passed on to her by SIM, specifically, in the of aspect medical services in the land; andrn(vi) SIM/ECWA was an agent of socio-economic transformation in IÌ€gboÌmiÌ€naÌ€ land as its Radio Eternal Love Winning All (ELWA) in Igbaja boosted the social status of the land and helped greatly to transform the people.rnrnThe study concluded that the growth of SIM/ECWA Mission in IÌ€gboÌmiÌ€naÌ€ land has not been static asits impacts have been felt all over IÌ€gboÌmiÌ€naÌ€ land. The study recommended that ECWA should work hard to sustain and improve upon SIM legacies in IÌ€gboÌmiÌ€naÌ€ land and that it should make efforts to resuscitate Radio ELWA for gospel broadcasting.