Background/Context: Women's sexuality, and the ways they experience it, has been a major topic in feminist theories and movements throughout history. For the more than 20,000 working-class women who participated in the Free Women movement in Spain (the libertarian women's movement, which started in 1936), women's sexuality was also a key topic in both their process of empowerment and their claims and activities. Purpose: The objective of this article is twofold. First, it explores the ways in which the Free Women movement helped improve the personal lives of women in that period. Second, this article analyzes how the libertarian women's movement contributed to the sexual education and encouraged other women to have sexual and affective relationships free of violence. Research Design: The article is constructed based on the life stories of two women who participated in the Free Women's movement. Our analysis also draws from an in-depth review of literature on the libertarian movement and sexual education as well as of historical documents about the libertarian movement of that time. Findings/Results: Our data reveal that thousands of women experienced personal transformations through their involvement in the libertarian movement, a social revolution that affected the entire society. Reflections on free love, the eradication of prostitution, and the promotion of "conscious motherhood" were leading ideas in both the educational activities that Free Women organized for working-class women and in the activists' own personal lives. These women's ideas on sexuality contributed to the creation of a society with more egalitarian and free relationships based on mutual support, solidarity, and collective and community-based action. This article shows how the Free Women were historically independent agents whose multiple achievements and transformations have been largely ignored. Conclusions/Recommendations: The article concludes by discussing how the main features of the Free Women's libertarian women's movement are present in the preventive socialization of gender violence that is currently being developed in some educational projects in Spain. In particular, the Free Women's contributions help students construct relationships free of violence.