This study examined the potential utility of adding items that assessed youths' emotional and behavioral disorders to a commonly used surveillance survey. The goal was to evaluate whether the added items could enhance understanding of youths' involvement in high-risk behaviors. A sample of 3,331 adolescents in Grades 8, 10, and 12 from four California school districts were coadministered a mental health screener and a youth surveillance survey. Items from both tools assessing chronic sadness and elevated mental health risk were significantly associated with increased risk of suicide ideation, cigarette use, alcohol use, binge drinking, marijuana use, physical fighting, being threatened or injured with a weapon, and skipping school. However, the addition of mental health content to the surveillance survey increased precision of understanding which youths were at the greatest odds of engaging in risk behaviors. Implications for practice and policy are discussed. (Contains 4 tables.)