This article introduces the concept of women’s cause field, which refers to the relational structure of groups mostly devoted to the advancement of women in a variety of social settings, cutting across the line between civil society and political institutions. Unlike the women’s movement, the women’s cause field encompasses a set of both extra-institutional and intra-institutional mobilizing structures. This concept expands on scholarship on institutional activism, and on field and network theory. Beyond the case of the women’s movement, it provides a new framework – the notion of cause field – to capture the architecture of specialized collective protest in the era of movement institutionalization, distinct from, and complementary to, the concept of social movement.