Families are the primary clients of public schools, but they are one of many constituencies who have a say in how schools actually operate. In all the technocratic fervor around "education reform"--the broad effort to implement standards and accountability, reform teacher tenure and evaluation, and increase parental choice--it is easy to lose sight of the fact that public schools are democratically controlled. Democratic control means that schools are as much a product of politics as they are of technical expertise. No matter how promising their reform ideas, advocacy groups who are unable to compete at the grassroots level will find it difficult to make their voices heard. In the past five years, however, school reform organizations and reform-minded funders have invested in organizing and activating parents to promote reform via grassroots political action. In the past year alone, several "parent power" efforts have made headlines in districts and states across the country, using mass rallies, lawsuits, petition drives, and canvassing campaigns to push for policy change. Despite all this activity, these efforts have not received much attention from researchers. Existing scholarly work on community organizing and education reform has focused on the effects that organizing has on schools, student achievement, and district policy. These are worthy questions, to be sure, but less is known about how these efforts get off the ground in the first place, how they successfully mobilize parents, and how they sustain their organizations over time. These questions are fundamental in light of well- established obstacles to political participation and collective action in low-income communities. This study provides a first look at these questions by going directly to the source: parent power groups themselves. The set of groups included is by no means a representative sample, but includes groups that reserve a primary role for parents in their advocacy work, that have statewide or multistate reach, and that were willing to share their time and insights. Drawing on more than 30 structured interviews, four site visits, and examination of primary source documents and data, this report provides a series of early lessons about how groups have structured their parent organizations, what strategies make for effective recruitment and mobilization, and what the challenges are for sustaining parent engagement over time.