What do women contribute when constitutions are written? How can they make their voices and proposals heard? Can feminism shape constitutional law? These are the main questions in the narrative of the feminist movement’s participation in the shaping of the 1991 Colombian Constitution. The objective of the essay is to recover the role of women in lawmaking while applying a gender lens to historical methodologies, by using documental evidence from the national archives and newspapers to uncover their actions and voices, as well as conducting interviews with feminist leaders in Colombia active during the 1990s. These findings show the repertoires of action of the women’s movement taking advantage of a crucial political opportunity to write constitutional law, as well as the obstacles and trade-offs they faced to advance women’s human rights in Colombia’s new charter. The essay argues that, despite the strategic feminist mobilization to include women’s reproductive rights in the Constitution, the political alliances outside (and inside) the National Constitutional Assembly between the Liberal Party and the Catholic Church blocked some of their demands, especially with regard to voluntary motherhood. The conclusions identify the feminist heritage of the new constitutional order that emerged as a result.