Based on Russian and French materials, a comparative analysis of the informational value of French and Soviet (archived in Russia) documents on the participation of Soviet citizens in the French Resistance was carried out for the first time, their authenticity and reliability were evaluated. In this article, the authors examined the difficulties of documenting the participation of Soviet people in the French Resistance during and after World War II. The authors showed how the processes of “liquidation” of the Resistance structures and the repatriation of displaced Soviet citizens caused lacunae in the archival holdings. The article reveals the history of the formation, description and use of documentary systems preserved in France and Russia about the participation of Soviet people in the Resistance, as well as the creation of their scientific and reference apparatus. The authors demonstrate how those sources were used in the historiography of the Resistance in various periods of Soviet history and Franco-Russian relations. The authors provided the most relevant information about the libraries, museums and archives that store and collect those documents; for the first time, recommendations are given for working with their scientific and reference apparatus, as well as an advice to Russian-speaking researchers of the Second World War, including the family history researchers.