This article aims to contribute to the developing area of feminist scholarship on women and political violence, through a study of women in one of Europe's oldest illegal armed movements, the radical Basque nationalist organization ETA. By tracing the changing patterns of women's participation in ETA over the past four decades, the article highlights the historical factors that help explain the choice of a small number of Basque women to participate directly in political violence, and shows how these factors have differed from those for men. While the gender politics of radical nationalism are intricately linked to cross-cultural associations of militarism with certain forms of masculinity, the article also stresses the importance of understanding women's activism in ETA in the context of the organization's characteristic as an ethnic nationalist movement, as well as the wider historical circumstances of the movement's development, including the modernization of Spanish and Basque society over the past four decades. Although comparisons with women in other armed movements are possible, such historical specificities undermine any attempt to construct a universal theory of women and ‘terrorism’, such as Robin Morgan's ‘couple terrorism’ thesis. Finally, the article examines the changing representations of female ETA activists in the Spanish and Basque media. Although women ETA activists are now regarded as ‘normal’, popular representations continue to link women's armed activism with deviant sexuality and the transgression of their natural destiny as mothers. The different treatment of women is evident as well in claims of sexual torture made by some detainees. The article concludes that although the participation of women in political violence poses disquieting questions for the largely anti-militarist women's movement, case studies of women in armed organizations, as well as their place in the wider practices of conflict, are an important contribution both to feminist debates about violence and to wider studies of political violence.