The module outlines the steps to be followed in the development and implementation of a child and adolescent mental health policy and plan. Its goal is to assist countries to promote the healthy development of children and adolescents. The module describes how to develop a policy and plan using several sources of data: country information about the epidemiology of child and adolescent mental health problems, the existing financial and human resources available, the current service organization and the views and attitudes of health workers. It then outlines the critical steps of formulating the vision, values, principles and the objectives of the policy, making use of an extensive consultation process with all stakeholders. In order to effectively implement the policy, a strategic plan should be developed, and guidance is provided on the key actions to be taken in this respect, including the formulation of strategies, associated activities, targets, indicators, resources and timeframes. Based on the latest evidence-based practice, the module provides a template that enables countries to address the comprehensive mental health needs of children and adolescents across a range of sectors. Also available: WHO Mental Health Policy and Service Guidance Package--14 modules Other modules included in the package: "Improving Access and Use of Psychotropic Medicines Mental Health Policy, Plans and Programmes. Updated version Mental Health Context Mental Health Financing Advocacy for Mental Health Quality Improvement for Mental Health Organization of Services for Mental Health Planning and Budgeting to Deliver Services for Mental Health Mental Health Legislation and Human Rights Mental Health Policies and Programmes in the Workplace Mental Health Information Systems Human Resources and Training in Mental Health Monitoring and Evaluation of Mental Health Policies and Plans"