Since 1991, the Centers for Disease Control and Prevention has administered the Youth Risk Behavior Survey (YRBS) biennially to representative samples of high school students. YRBS results indicate that health-risk behaviors often developed during middle school years. To date, few state and local education agencies have administered the YRBS-Middle School. This study measured prevalence of health-risk behaviors among middle school students in a large, majority-minority school district (n=1,783). Results indicated that young adolescents (ages 11–14) are engaging in multiple health-risk behaviors. For example, 24.4% seriously considered committing suicide in the previous year, 53.3% had been in a physical fight, 50.2% ever drank alcohol, 17.9% ever used marijuana, and 13.4% had already had sex. Such behaviors potentially could lead to serious consequences related to their educational achievement and overall health status. Health-related policy and program applications are discussed.