This guide has been developed to assist donor agencies and policy advisors in a range of organisations working with and for youth. It aims to increase understanding of the growing importance of, and greater potential for, youth participation in development practice and to explore key issues and approaches. It provides information on how to actually work with youth at a practical operational level in respect of policy and programming. It does this through the provision of promising practice case studies (and their associated resources) and a number of quality standards that will help organisations to get started. Central to the guide is its focus on working with excluded sub-groups of young people, and the importance of building partnerships between adults and youth in a culturally sensitive manner.