Establishing legitimate political leadership through non-violent means is an essential step in the rebuilding of post-conflict societies. For this reason the successful holding of democratic elections is often seen as the crowning achievement of the peace process. In recent years, however, it has become clear that elections do not always guarantee the peace, and may in fact, make societies more dangerous.1 This has prompted political scientists to look more closely at other dimensions of the transition from violent conflict to democratic politics, including the role of political parties. Political parties play an essential role in all democracies, but their importance is magnified in conflict-prone societies. While some scholars have argued that political parties may help to consolidate peace by forming coalitions between groups formerly in conflict, more recent research suggests that such parties may also entrench social cleavages, especially if party formation is based along former conflict fault lines. This article considers these arguments in the case of Aceh, Indonesia, where an historic peace agreement allowed former Acehnese rebels to form their own political party-one based along both ethnic and former conflict lines.