China's rapid urbanization has created opportunities for many peoplepredominantly men -to migrate from rural to urban areas in search of work, leaving their farms and families. This has resulted in many villages being dominated by a large population of 'left-behind' women. This situation has required these women not only to take responsibility for their own domestic and farming duties, but also increasingly to get involved in local governance, particularly in trying to prevent the appropriation of collective natural resources. Based on a case study in a typical village in central China, this paper explores an example of women's collective action to prevent the over-exploitation of collectively owned sand resources. As the case study illustrates, although previously denied the opportunity to participate in local politics and governance, the 'left behind' women have seized the initiative and have demonstrated the capacity to impose their will, through a mix of toughness, flexibility and endurance. As a consequence, the study demonstrates that, when empowered to act, the left-behind women are as capable as anyone of defending their community's resources. This new approach to collective action over natural resource management therefore suggests that rural-urban migration has not been a wholly negative phenomenon for those left behind. On the contrary, it has created a space in which those who were previously denied access to local politics can assert not only their right to govern, but also their aptitude for the types of action that are required to defend collectively-owned resources.