This study reported the development and validation of the Social Identities and Attitudes Scale (SIAS), a stereotype threat susceptibility measure. Exploratory and confirmatory factor analyses conducted with college students indicate that the scale possesses strong psychometric properties. The SIAS explained 65% of the variance in the items measuring ST susceptibility, with subscales demonstrating acceptable levels discriminant and convergent validity and reliabilities ranging from 0.81 to 0.94. Future researchers could use the SIAS to establish a baseline for measuring ST susceptibility, differentiate between levels of ST risk (e.g. low, moderate, high), and eventually develop specialized interventions for different ST risk levels. (Contains 8 tables.)