Women are under-represented at the highest levels of leadership in health care, so many institutions have started forming "women in medicine" affinity groups. In this The Clinical Teacher's Toolbox, we review the history of women's professional peer-to-peer networking groups in health care, describe the rationale for establishing a women's group, discuss the goals and common content covered by successful women's groups, share best practices on forming and sustaining women's groups, and describe common pitfalls to avoid. When forming a women's group, identifying the group's vision, mission, and primary aim statements are important, and early meetings should deliberately establish a tone of inclusion. We acknowledge that the term "women's groups" implies that gender identity is binary - in reality, these groups are for all who want to combat gender inequities in health care. While early stages of women's groups typically focus on community-building, peer networking, and inviting guest speakers to speak about relevant topics, successful groups often ultimately pivot to advocacy, internal capacity-building, evaluation, and dissemination. To sustain and maintain the group, succession planning, regular opportunities for evaluation, and deliberate planning are essential. Although usual principles of successful small group creation apply, this article outlines unique considerations for how women's groups can advance gender equity.