Contemporary mental health assessment conceptualizations focus on both well-being and distress. This study presents initial validation information for the "Social Emotional Distress Survey--Secondary" (SEDS-S), which was designed for school-based complete mental health screening that employs brief self-report measures of well-being and distress. The SEDS-S structure was investigated using two independent samples of U.S. high school students (N = 3,780). Findings from exploratory and confirmatory factor analyses suggested a one-factor model of distress with good model fit. Path analyses revealed significant positive relations of the SEDS-S distress factor with symptoms of anxiety and depression, and a significant negative relation with life satisfaction and strengths scores. Future research directions and use in school-based screening applications are discussed. [For the corresponding grantee submission, see ED585101.]