Mental health problems affect 10-20% of children and adolescents worldwide. Despite their relevance as a leading cause of health-related disability in this age group and their longlasting effects throughout life, the mental health needs of children and adolescents are neglected, especially in low-income and middle-income countries. In this report we review the evidence and the gaps in the published work in terms of prevalence, risk and protective factors, and interventions to prevent and treat childhood and adolescent mental health problems. We also discuss barriers to, and approaches for, the implementation of such strategies in low-resource settings. Action is imperative to reduce the burden of mental health problems in future generations and to allow for the full development of vulnerable children and adolescents worldwide. Copyright © 2011 Elsevier Ltd. All rights reserved.