This paper analyses the process of institutionalization of a new public sector accounting system. Taking the Cape Verdean Central Government as setting, it seeks to understand what have been the main factors interfering in the reform, how such action has led to the institutionalization of the system currently in force, and how it may determine future reforms. From the theoretical perspective of contingency, several stimuli drive the reform of public sector accounting in emerging countries. In Cape Verde, they have been: changes in the political regime, the dominating doctrine of business accounting, financial pressures, and requirement of a wider public sector reform. In the light of institutional perspectives, behaviors of seeking for legitimacy and presence of mimetic and coercive forces in the reforms, have been evident. This study makes other countries with similar contexts and under public sector accounting reforms, aware of how to promote and manage these processes successfully.