This study examines Nigeria-South Africa relations based on the themes of cooperation, confrontation and competition. It examines the origin, dynamism and challenges of Nigeria-South Africa relations putting in realist perspective, South Africa's perceived confrontational foreign policy which negates the principle of reciprocity. Hence the adoption of the realist theory which argues that Nigeria-South Africa relations should be conducted on the basis of national interest backed by elements of power. A combination of qualitative method was engaged in this study, and the chronological scope of the study is 1994-2017. It is recommended that South Africans especially their youths be educated on the role Nigeria played in their liberation struggle while Nigeria should concern herself with improving her image as the 'giant of Africa', and work hard to develop infrastructure, diversify her economy and adapt to the dynamic foreign policy environments of the 21st century.