Policies to create more age-friendly environments, in which a growing number of cities and communities, local authorities and regional governments participate, have become a forceful movement in Europe and globally. These policies explore synergies between improving the physical environment of neighbourhoods, transport and housing; increasing respect, social inclusion and community participation; and investing in public services. This publication provides a toolbox to guide local policy-makers and planners in developing, implementing and evaluating age-friendly policies and interventions – policies that support people to age actively and healthily and thus both to do the things that are important to them and to contribute to their communities. Based on lessons learned from existing age-friendly initiatives in Europe, this publication summarizes key factors for establishing and sustaining successful initiatives within four phases of the policy process: engaging, planning, implementing and evaluating. A wealth of examples illustrates how local governments have put the principles of age-friendly action into practice.