Abstract The study examines the involvement of the parliaments in foreign policy and diplomacy, particularly, the Nigerian National Assembly, from 1999-2011. From a protracted military interregnum, Nigeria returned to democratic governance in 1999; and thence on the Nigerian National Assembly has stamped its feet on the conduct of Nigeria’s foreign policy and diplomacy. This study investigates the extent to which the Nigerian National Assembly has influenced and complemented the executive authority in the conduct of the Nigerian external affairs. The study adopts qualitative approach, anchored on constitutional provisions, parliamentary debates, committee reports, motions, resolutions, judicial decisions and secondary sources. The findings shows that the Nigerian constitution provides the National Assembly considerable powers in foreign policy and diplomacy, particularly in: confirmation of appointments of Ambassadors and others that are foreign related, including the minister of foreign affairs, treaty ratification, budgetary approval, oversight and declaration of war and deployment of troops on peace-keeping. Despite these clear involvements of the National Assembly, the executive dominance still persists, while the paper argues that the Nigerian experience is a reflection of broader bottlenecks facing parliaments across emerging democracies. This paper contributes to a deeper understanding of the role the Nigerian National Assembly is expected to play in Nigeria’s foreign policy, and diplomacy.