Nigeria’s governance structure comprises three arms of government: the legislature, executive and judiciary. The Constitution vests each arm with specific roles in consonance with the doctrine of separation of powers. Reciprocal checks and balances in the governing system is an important feature of separation of powers. The legislature checks the other organs, and vice versa. The goal is to ensure accountability in governance. One way by which the legislature ensures accountability of the executive is through the impeachment process. This power is vested in a bicameral legislature at the federal level – the National Assembly (NASS). This paper, a desk review, appraises the impeachment power of the National Assembly as provided for in the Constitution. It examines the extent to which this power has been employed to ensure the accountability of the executive under the present democratic dispensation. It argues that the National Assembly has failed to utilise its power of impeachment because it has been compromised due to its own accountability deficit. It recommends, among others, that the NASS should strive to conduct the business of the Assembly in a manner that preserves the integrity of the legislature and avoids conflicts of interest. This way, it can muster the moral strength and political will needed for the pursuit of impeachment of the executive.