The modern Polish–Ukrainian dialogue is the second interstate dialogue of the twentieth century, in the development of which the historical and political discourses have played an important role. The so-called Volhynia discourse poses the most serious challenge in this dialogue, while at the same time being its main component. The article claims the Volhynia discourse plays a major role in bringing about the asymmetry of historical memory between the two states. The events of Volhynia-43 have remained in Polish historical memory as an act of genocide perpetrated in 1941–1943 by Ukrainian nationalists, mainly from the Ukrainian Insurgent Army (UPA), on over 100,000 Poles and citizens of the Polish state inhabiting Galicia and Eastern Małopolska, including Volhynia. These territories, considered by the Ukrainian nationalist party OUN as indigenously Ukrainian, were to be included in the future independent Ukrainian state. The Ukrainian historiography, apart from sparse exceptions, avoids the term ‘massacre’ and ‘genocide’ in reference to the events in Volhynia, defining them as a conflict or a Polish–Ukrainian war with a comparable number of casualties on both sides. The article, analysing speeches and announcements by political leaders of Poland and Ukraine, focuses on explaining the causes and effects of this shift in accentuation in the Ukrainian discourse on Volhynia, and, broadly, in Ukraine working through its past.