In the following contribution, the author analyses the sources and databases of the dead and missing Slovenians who lost their lives as members of the Italian armed forces or as Italian soldiers of Slovenian nationality in war captivity during World War II and after it. The Slovenian and Italian databases, resulting from many years of research efforts, represented the primary sources for the author. She underlines the Slovenian national collection Casualties of World War II in Slovenia (titled Fatalities among the Population in the Territory of the Republic of Slovenia During and Immediately after World War II), created by the researchers from the Institute of Contemporary History; and the Italian database Banca Dati dei Caduti e Dispersi 2a guerra Mondiale, created by the researchers of the Archive of the General Commissariat for War Graves Care (Commissariato Generale per le Onoranze ai Caduti) of the Italian Ministry of Defence. Almost a hundred years have passed since Slovenians from the Littoral Region were first drafted into the Italian armed forces between the world wars. As Slovenians in the Italian Army were among the first Slovenian casualties of war in the interwar period (in 1935) and during World War II (in 1940), this contribution analyses the current state of the basic lists and sources regarding the fatalities, their numbers and names, as well as examines the possibilities of assisting the victims among the Slovenians mobilised into the Italian armed forces and their families with more detailed lists and by honouring their memory.