All forms of violence, including youth violence, suicidal behavior, child maltreatment, sexual violence, intimate partner violence, and elder abuse, negatively affect the health and well-being of this country. Youth violence, in particular, is a significant public health problem. Many young people and communities view the grim facts about youth violence as unavoidable and have accepted youth violence as a societal reality. However, the truth is that youth violence is not inevitable. Youth violence is preventable. The past investment into monitoring, understanding, and preventing youth violence is paying off and proving that youth violence can be stopped before it occurs. the Centers for Disease Control and Prevention (CDC) and the larger field of youth violence prevention researchers and practitioners have performed decades of work on youth violence and how it can be prevented. From systematic surveillance, rigorous research on modifiable factors that predict violence, evaluation of prevention strategies, and the strengthening of the capacity of communities to use approaches that work, a great deal has been learned about how to prevent youth violence. To help communities take advantage of the available knowledge, CDC has developed "Preventing Youth Violence: Opportunities for Action." This resource summarizes what is currently known about youth violence--the health consequences, trends, disparities, causes, costs, and prevention strategies. It outlines important strategies for youth violence prevention that are based on strong evidence and experience. It includes examples of specific programs and activities that have been found to be effective. These evidence-based youth violence prevention strategies focus on reducing the factors that put young people at risk for violence and bolstering the factors that strengthen their positive development and buffer against violence. Everyone has a role to play in preventing youth violence. "Preventing Youth Violence: Opportunities for Action" provides information and action steps that can help public health and other community leaders work with partners to prevent youth violence. This resource also describes actions that young people, families, caregivers, adults who work with youth, and other community members can take to reduce youth violence. "Development of 'Preventing Youth Violence: Opportunities for Action'" is appended.