In Nigeria the constitutional role of the Legislature is yet to receive adequate scholarly attention. The main area of focus in most literature has been the executive arm of government and its other related activities. This paper examined the evolution of legislative functions in Nigeria with a view to justifying its contributions to democracy especially in the first, second and fourth republics (1960-2003) respectively. Related concepts of legislature and democracy were clearly explained with concrete supportive scholarly literature. The historical evolution of legislative function in Nigeria was also explored to demonstrate the common but often neglected place of the legislature in democratic governance. Based on this, premise, proper constitutional roles of the legislature in the promotion of democracy in Nigeria were analysed to show clearly that democratic culture cannot be sustained without harmonious executive and legislature partnership. The prospects of this partnership were outlined with far reaching recommendations on how to promote healthy executive and legislature working relationship in present democratic dispensation in Nigeria. Keywords: Legislature, democracy, constitution, history and role.