The Youth Risk Behavior Survey (YRBS) is used by the United States Centers for Disease Control to estimate rates of suicidal thoughts and behaviors in adolescents. This study investigated the validity of the YRBS suicidality items by examining their relationship to criterion variables including loneliness, anxiety, depression, substance use, and other suicidality items. Participants were 386 high-school students. YRBS items assessing suicidal thoughts and behaviors demonstrated good convergent and discriminant validity. (Contains 1 table.)