Background: Early identification can greatly impact the trajectory of eating disorders, and school-based screening is 1 avenue for identifying those at risk. To be feasible in a school setting, a screening program must use a brief, valid screening tool. The aim of this study was to assess how well brief attitudinal and behavioral survey items identify adolescents at risk in a large sample of high school students from across the United States. Methods: Data were drawn from the National Eating Disorder Screening Program, the first-ever national eating disorders screening initiative for US high schools. A 2-stage, clustered sampling method was used to randomly select a subset of student screening forms (n = 5740), which included the Eating Attitudes Test (EAT-26), behavioral questions assessing the frequency of vomiting and binge eating in the past 3 months, and an attitudinal item that assessed preoccupation with thinness. Results: Nearly 12% of females and 3% of males reported vomiting to control their weight and 17% of females and 10% of males reported binge eating 1 or more times per month. Approximately 24% of females and 8% of males report being preoccupied with being thinner. We found that the attitudinal measure yielded high sensitivity and specificity. Combined screening measures that used both the attitudinal and behavioral items yielded slightly higher sensitivity values than those found with the attitudinal measure alone. Conclusion: High school administrators should include items that assess both preoccupation with thinness as well as behavioral items that deal with eating disorders on student health surveys. (Contains 2 tables.)