At a time when some corporate women leaders are advocating for their aspiring sisters to ‘lean in’ for a bigger piece of the existing pie, this book puts the spotlight on the deep structures of organizational culture that hold gender inequality in place. Gender at Work: Theory and Practice for 21st Century Organizations makes a compelling case that transforming the unspoken, informal institutional norms that perpetuate gender inequality in organizations is key to achieving gender equitable outcomes for all. The book is based on the authors’ interviews with 30 leaders who broke new ground on gender equality in organizations, international case studies crafted from consultations and organizational evaluations, and lessons from nearly fifteen years of experience of Gender at Work, a learning collaborative of 30 gender equality experts. From the Dalit women’s groups in India who fought structural discrimination in the largest ‘right to work’ program in the world, to the intrepid activists who challenged the powerful members of the UN Security Council to define mass rape as a tactic of war, the trajectories and analysis in this book will inspire readers to understand and chip away at the deep structures of gender discrimination in organizational policies, practices and outcomes. Designed for practitioners, policy makers, donors, students and researchers looking at gender, development and organizational change, this book offers readers a widely tested tool of analysis – the Gender at Work Analytical Framework – to assess the often invisible structures of gender bias in organizations and to map desired strategies and change processes.