Public authorities at different levels of governance are increasing the opportunities for citizens to deliberate on issues of public policy. With this practice comes a plethora of academic evaluations, influenced particularly by theories of deliberative democracy. However, the perspectives of one significant group of actors have generally been overlooked: the professional participation practitioners who are commissioned to organize and facilitate these events. It is these actors who work with public authorities in designing and implementing engagement strategies and who thus structure the democratic experience of those citizens who participate. Drawing on interviews with experienced practitioners in Britain and Germany, this essay explores the degree of diffusion of public participation designs; the extent to which practitioners express deliberative democratic principles; and the constraints they perceive to more effective institutionalization of public participation. While practitioners are committed to democratic ideals, too often the culture and practices of public authorities, as well as the pressures of the market-place, constrain their realization.