The Commission on Women and Health was formed in 2012. A partnership between The Lancet, the Women and Health Initiative at the Harvard T.H. Chan School of Public Health, and the University of Pennsylvania School of Nursing, the Commission aimed to review and generate evidence and develop a strategic framework for the women and health agenda. Women and health is a novel concept that refers to the multifaceted ways in which women and health interact, moving beyond a narrow focus on women’s health to address the roles of women as both users and providers of health care. Innovative approaches are needed to improve the health of women and girls and ensure that they are supported and valued in their multiple roles in society. Girls and women who reach their full potential make significant contributions to their own, their families’ and their communities’ health and wellbeing and are the key to sustainable development.