As pointed out by Roeder and Rothchild (P. G. Roeder and D. Rothchild (eds), Sustainable Peace: Power and Democracy after Civil Wars (New York: Cornell University Press 2005)), a crucial dilemma in post-war power-sharing arrangements is that the very same institutions that provide an attractive basis for ending a conflict are likely to hinder the consolidation of peace and democracy in the long term. The 2005 Comprehensive Peace Agreement (CPA) was the major reason for ending Sudan's North–South civil war – for ‘winning the war’ – but did also create the conditions for ‘losing the peace’? This article looks at the power-sharing arrangements of the CPA and its impact on the conditions from peace and democracy in Sudan in the interim period prior to the referendum on southern independence. Through analyses of its formal institutional frames, its implementation, and the major stakeholders' perceptions, it becomes clear that the power sharing did not ‘make unity attractive’, as initially anticipated, but was in fact one of the factors contributing to the separation of Sudan in 2011.