Federalism in Nigeria dates back to 1951 (69 years), but in spite of the long period of experience with federalism as a political system, Nigerians are still in search of an acceptable, truly and functional federal constitution. Today, the clamor for the restructuring of the Nigerian federal system, another way of asking for a new constitution, is so rife that it has assumed a crisis proportion. This paper therefore briefly discusses some conceptual notes of federalism and summarizes the federal constitutions in Nigeria from 1951 till date. And finally, the paper adopts four perspectives in explaining the challenges of Nigerian federalism. The four perspectives are (1) the political economy of constitution making, (2) the nature of the Nigerian state, (3) the absence of hegemony and (4) the military factor.
Key words: Nigeria, federalism, constitutional engineering, political system.