Tracking the frequency with which governments have used lethal or non-lethal violence during protests, it can be shown that governments in Southeast Europe appear to have become more tolerant of this type of extra-parliamentary political participation. Data collected from protest events shows that at least since the early 2000s there has been a period of government restraint. This came at the same time as the EU opened accession pathways for most countries in the region. Thus, the thesis discusses the reasons for the decline in repression. It explores whether the temporal correlation between increased EU engagement and the decline of physical repression in the region was coincidental or can be linked. In this context, the thesis focuses on the role of EU-accession conditionality, since it has been assumed that EU conditionality could have a democratizing and, therefore, potentially constraining effect on governments. Even though the thesis concludes that EU-accession conditionality impacted repression, the nature of that impact is complex. It shows that to understand how EU-accession conditionality impacted repression, we cannot treat repression as a monolithic concept. Although EU conditionality reduced visible forms of repression, such as lethal and non-lethal violence, it had little effect on opaque, institutional forms of repression.