Research projects demonstrating ways to improve health services often fail to have an impact on what national health programmes actually do. An approach to evidence-based policy development has been launched in Ghana which bridges the gap between research and programme implementation. After nearly two decades of national debate and investigation into appropriate strategies for service delivery at the periphery, the Community-based Health Planning and Services (CHPS) Initiative has employed strategies tested in the successful Navrongo experiment to guide national health reforms that mobilize volunteerism, resources and cultural institutions for supporting community-based primary health care. Over a 2-year period, 104 out of the 110 districts in Ghana started CHPS. This paper reviews the development of the CHPS initiative, describes the processes of implementation and relates the initiative to the principles of scaling up organizational change which it embraces. Evidence from the national monitoring and evaluation programme provides insights into CHPS' success and identifies constraints on future progress.