This article presents the Konstanz One-Sided Violence Event Dataset (KOSVED) which allows researchers to study the dynamics of civilian abuse in 17 civil wars. The dataset provides, based on a multitude of sources, detailed information on the number of civilians killed or harmed by government or rebel troops. Where information is available, KOSVED also documents the dates of these events as well as the identities of the perpetrators and the means used in terrorizing the civilian population. The authors argue that the content analysis of news reports offers relatively accurate figures on those events that the perpetrators cannot hide from the public and that receive prominent media attention. Presumably, such information motivates potential short-term retaliatory acts by the group that has been the target of one-sided violence. The analysis suggests that, over the course of a conflict, almost all actors attack unarmed citizens, although to radically different degrees and relying on different means.