Abstract During the Holocaust, thousands of Jews in France fled Europe via Franco’s Spain. When leaving France, refugees who lacked the required travel documents avoided police and customs officers at the Franco-Spanish border by walking over the Pyrenees. Guides (passeurs) led them through the mountains to the border, choosing trails and times that would make encounters with police patrols less likely. Most charged large sums of money, but some worked without payment. This article explores why the latter group engaged in this dangerous form of rescue, by examining how they became border guides. It focuses on two French farmers, a French Christian brother at a sanatorium, and an antifascist activist from Germany. The sources analyzed include the memoirs, unpublished accounts, diaries, letters and oral history interviews of the guides, their work associates, and the refugees; as well as official correspondence between French police and government officials in the Pyrenees region, and the archival records of the Brothers of the Christian Schools. The author’s primary research finding is that the border guides considered in this study undertook the dangerous task of guiding refugees because they had had a series of experiences and had engaged in a series of actions that made it more feasible for them to do so when asked. Their values and understanding of their work also help explain why they became guides. Reflections on the implications of this research for our comprehension of bystanders’ actions conclude the article.