This article outlines and tackles two inter-related puzzles regarding the comparatively much less robust human rights impact that the ECOWAS Court (in effect, West Africa’s international human rights court) has had on the generally more democratic legislative/judicial branch of decision-making and action in Nigeria vis-à-vis the generally more authoritarian executive branch within Nigeria, the country that is the source of most of the cases filed before the court. The article then discusses and analyzes the examples and extent of the court’s human rights impact on legislative/judicial branch decision-making and action in that key country. This is followed by the development of a set of analytical, multi-factorial, explanations for the two inter-connected puzzles that animate the enquiry in this article. In the end, the article argues that several factors have combined to produce the comparatively much less robust human rights impact that the ECOWAS Court has had on domestic legislative and judicial decision-making, process, and action in Nigeria, through restricting the extent to which the latter could mobilize more robustly the court’s human rights-relevant processes and rulings.