This book unpacks two decades of Nigeria's National Assembly spanning 4th-8th legislative sessions. It focuses on the core areas of legislative functions - lawmaking, appropriation, oversight and representation - in examining the achievements, challenges and prospects of the legislature. This is particularly important because Nigeria being the most populous country in Africa is a crucial bastion of democratic governance in the region. Therefore, conducting deep diagnostics of the federal legislature as the custodian of popular mandate and the anchor of accountability offered immense opportunity for learning that would catalyze further institutional reforms and democratic consolidation.