This chapter examined the Role of Agricultural Transformation Agenda Support Programme Phase-1 in Promoting Agricultural Extension Service Delivery. The chapter also examined the concept and focus of ATASP-1, Goals of ATASP-1, Historical Development of ATASP-1, The Extension aspect of ATASP-1, Roles of ATASP-1 in promoting agricultural extension service delivery, Nature of the roles played by ATASP-1, Challenges of ATASP-1 programme implementation, Issues affecting national agricultural programmes and policies and ways of addressing the issues associated with the implementation of agricultural programmes in Nigeria. In conclusion therefore, it was found out that ATASP-1impacted positively and significantly on the livelihood of the participating farmers.