The purpose of this special issue is to draw together strands of the conversations about evidence, policy, guidance, process and best practice; and to help practitioners, researchers and policy makers make the links between the health of the child and the health of the city. The research, ideas and case studies discussed in this special issue contribute to building a better understanding and alignment of planning with children’s needs and perspectives. In doing so, it highlights what does and does not work well for healthy and child-friendly cities and the challenges that are still to be overcome.