Abstract: This paper aimed at exploring reasons to why policies change in Nigeria. It defined policy as action taken toward problem solving by government or an organization. It also defined policy change as the replacement of one or more existing policies with another. The paper adopted advocacy coalition framework as theoretical frame work and explained policy change. The theory explained that policy change occurs through interactions between wide external changes or shocks to the political system and the success of the ideas in the coalitions, which may cause actors in the advocacy coalition to shift coalitions. More so, the paper discussed six reasons to why policies change in Nigeria, these reasons are: failure of the existing policy to accomplish it set objective, political instability, ineffective and corrupt political leadership, policy diffusion, change in structure and socio-economic factors. And finally the paper recommended that for a policy to fully achieve its set goal and objective, there should be continuity of policy implementation irrespective of the person or political party in office, proper assessment and implementation of policy will also reduce the risk of policy failure and also policy makers should have the people at heart and not use the predicament of the people for personal gain.