A range of interest groups, including civil society actors, are playing an ever more important role in shaping and delivering public health policy at both national and international levels in many countries. Although this process is making public health policy making more complex and less predictable as nation-states and individual governments have lost a degree of power to transnational business corporations and global civil society organizations, it also offers public health professionals and advocates new avenues for promoting their messages and delivering essential services in new ways.