School health programmes have been demonstrated to be the most cost-effective way to influence health behaviours in young people. The purpose of this two-part handbook is to support schools as they seek to implement interventions aimed at reducing the main modifiable risk behaviours for noncommunicable diseases (NCDs) . The background provided in this Introduction handbook and the approaches and advice outlined in the Practical application handbook focuses on providing young people with the knowledge, attitudes, beliefs and life skills necessary for making informed decisions, and creating a healthy school environment that can reduce the risk of NCDs