In this article we examine attitudes of ethnonationalism in two countries that have experienced ethnic civil war: Bosnia-Herzegovina and Kosovo. We analyse the strength of attitudes of ethnonationalism on the individual level, and how ethnonationalism is related to local ethnic settlement patterns and previous experiences of local inter-ethnic violence. We combine data at the municipality level with data from the South-East European Social Survey Program from 2003 and conduct a multilevel analysis for each case. In both cases, ethnonationalism dominates, but it is stronger in Kosovo than in Bosnia-Herzegovina. We find a clear difference between members of local majorities and minorities, but the effect in Bosnia-Herzegovina is the opposite of the effect in Kosovo. In Bosnia-Herzegovina, members of both minority and majority groups tend to be more ethnonationalist the larger their group. Contrary to our initial expectations, people express less ethnonationalism in municipalities that were more severely hit by violence, whereas in Kosovo no effect of local violence can be found. The more recent conflict and less consolidated institutions in Kosovo may help explain these divergent results. Still, the lack of consistent findings makes it hard to infer beyond the two cases examined.