This study examined the association between survey responses to health behaviors, personality/psychosocial factors, and self-reported sexually transmitted infections (STIs) to create a brief survey to identify youth at risk for contracting STIs. Participants included 200 racially diverse 14- to 18-year-old patients from a pediatric primary care clinic. Two sexual behavior variables and one peer norm variable were used to differentiate subgroups of individuals at risk of contracting a STI based on reported history of STIs using probability (decision tree) analyses. These items, as well as sexual orientation and having ever had oral sex, were used to create a brief sexual health screening (BSHS) survey. Each point increase in total BSHS score was associated with exponential growth in the percentage of sexually active adolescents reporting STIs. Findings suggest that the BSHS could serve as a useful tool for clinicians to quickly and accurately detect sexual risk among adolescent patients.