Parents play a fundamental role in shaping children's development, including their dietary and physical activity behaviors. Yet family-centered interventions are rarely used in obesity prevention research. Less than half of childhood obesity prevention programs include parents, and those that do include parents or a family component seldom focus on sustainable change at the level of the family. The general absence of a family-centered approach may be explained by persistent challenges in engaging parents and families and the absence of an intervention framework explicitly designed to foster family-centered programs. The Family-centered Action Model of Intervention Layout and Implementation, or FAMILI, was developed to address these needs. FAMILI draws on theories of family development to frame research and intervention design, uses a mixed-methods approach to conduct ecologically valid research, and positions family members as active participants in the development, implementation, and evaluation of family-centered obesity prevention programs. FAMILI is intended to facilitate the development of culturally responsive and sustainable prevention programs with the potential to improve outcomes. Although childhood obesity was used to illustrate the application of FAMILI, this model can be used to address a range of child health problems.