During the Second World War, both Italy and the Holy See were well-positioned to observe events taking place in the Independent State of Croatia. The Italian military operated in the territories of the Independent State of Croatia (Nezavisna Država Hrvatska – NDH). At the same time, Italian diplomats, representatives of the National Fascist Party, and the “apostolic visitor” sent by Pope Pius XII were stationed in Zagreb. Taken together, the Italian military and diplomatic archives (L’Archivio dell’Ufficio Storico dello Stato Maggiore dell’Esercito and Archivio Storico Diplomatico degli Affari Esteri), along with recently declassified documents from the Vatican archives (Archivio Apostolico Vaticano and Archivio Storico della Segreteria di Stato), not only shed light on different views on Ustasha violence but also indicate when and how the violence was (or wasn’t) documented. The comparative approach highlights the conflict between the Italian military—both individual soldiers and commanding officers—who generally opposed Ustasha violence, and Italian diplomats, along with high-ranking members of the Fascist Party, who either supported the Ustasha regime or ’preferred not to antagonize it. The Vatican archives help us understand how much the Holy See knew about the events in the Independent State of Croatia and how this information traveled. Furthermore, the Vatican archives point to a shift that began in early 1943. The failure of the initial calculation that the Axis would win the war led the Holy See to gather materials aimed at countering “propaganda” regarding the actions of the Catholic clergy in Croatia. This seems to have been part of the larger realization that the Roman Catholic Church would face scrutiny after the war. Lastly, the article explores how photographic albums created by the Italian military serve as important visual evidence in tracing the flow of information regarding the genocide in the ISC.