The repository contains the cleaned and labelled data, the codebook, and the sample questionnaire of a 2018 public opinion survey conducted in six Southeast European countries: Bosnia and Herzegovina, Croatia, Kosovo, North Macedonia, Montenegro, and Serbia. This survey captures the experiences of respondents and people close to them during the wars that followed the dissolution of Yugoslavia in the 1990s, and how they look back on these conflicts. In addition, the data contains people’s political views on issues such as nationalism, patriotism, economic policy, and interethnic relations. Finally, the survey measures the political behavior of participants, such as their electoral choices, news and media consumption, and the forms of political participation they engage in.