This article explores the literature on democratization to account for the proscription of political parties in democratizing states. A survey of 22 party bans in 12 European states identifies two distinct classes of proscription derived from the ‘degree of democratization’ present in a banning state. I identify features of ‘new’ and ‘incomplete’ democracies that help explain proscription. Case studies on Germany, Austria, Russia, Latvia and Greece illustrate the impact of ‘modes of transition’, heightened uncertainty, political tensions and instability on ‘new democracy bans’, and the impact of illiberalism, limited checks on executive power and circumscribed political participation on ‘incomplete democracy bans’.