The topic of this paper is electoral system design for societies that have recently experienced armed conflict where frontlines have coincided with ethnic boundaries. In conflicts of this character, the salience of ethnicity increases in the society. The paper argues, however, that this should not be seen as a fixed condition. Ethnic divisions must be addressed in the building of new political institutions; this is important for the legitimacy of the institutions, and thus for social stability. However, there is a danger that political institutions are formed on the implicit assumption that the current pattern and intensity of divisions is permanent. When this happens, important opportunities for peacebuilding may be lost. Consequently, the paper also argues that the level of sensitivity to conflict patterns on the part of the authorities designing the new institutions can make or break a peace process. Ethnic divisions must be addressed, but one must also aim to reduce their salience. The way to do this, in terms of electoral system design, is to shape systems that are representative, but also flexible. Ideally, the electoral system should itself contribute towards de-ethnicization of politics, and furthermore it should be shaped in such a way that it does not fixate the accentuation on ethnicity in politics, or counteract achievements to this effect in other sectors of society.