Evidence-based treatments and preventive interventions in the child and family area have not met with widespread adoption by practitioners. Despite the high prevalence of child behavioral and emotional problems, many parents and families in need are not receiving or participating in services, and when they do, the most efficacious interventions are not what is usually provided. Simultaneously addressing the issues of low penetration and insufficient dissemination of evidence-based programming requires a population approach to parenting and family support and intervention. Process issues are important, particularly in relation to engagement of stakeholders, recruitment of practitioners, consideration of organizational factors, and use of media and communication strategies. This article discusses why there is a need for a population-based approach, provides a framework of how to conceptualize such an approach, and describes an example from our own work of a recently initiated prevention trial that illustrates a population-based approach in action. The rationale, structure, and goals of the Triple P System Population Trial are described in the context of the aforementioned population framework.