This article analyzes the status of difficult historic events in Ukrainian collective memory. Difficult elements of collective memory are defined as those which divide society on basic matters, such as identity and national cohesion, and events which are being actively forgotten because of the role of Ukrainians as perpetrators. Three such issues were analyzed: World War II and the role of the Ukrainian Insurgent Army (UPA), the Holocaust, and the ethnic purge of Poles in Volhynia and Eastern Galicia in 1943–1945. Utilizing data from quantitative and qualitative studies, the author showcases the significance of these issues for contemporary Ukrainian identity and Ukraine's relations with its neighbors. In particular, the evaluation of World War II and the role of the UPA in Ukrainian history polarizes Ukrainian society to a great degree. At the same time, this element of national history is used to construct a common, anti-Russian identity. The difficulty of relating to the memory of the Holocaust and the ethnic purge in Volhynia is of a different character. These events are problematic for Ukrainian collective memory because they demand a painful settling of accounts with the past. At present, only Ukrainian elites are willing to work on these subjects, and only to a limited degree, while the common consciousness either denies or ignores them altogether.