Validated measures that can be administered to school populations are needed to advance knowledge of help-seeking processes and to evaluate suicide prevention programs that target help-seeking. With 6,370 students from 22 high schools, we assessed the psychometric properties of three brief measures: Help-Seeking Acceptability at School, Adult Help for Suicidal Youth, and Reject Codes of Silence. Internal consistency coefficients ranged from 0.64 to 0.84. In support of construct validity, lower scores on each scale were associated with more maladaptive coping norms; for each one unit increase on each scale, students were one third to one half as likely to report suicidal ideation, suicide attempts, and elevated depression.