This article describes two separate studies that were conducted to develop and validate a measure of the prolonged stress activation and anticipatory race-related stress response in African American adults (Prolonged Activation and Anticipatory Race-Related Stress Scale [PARS]). In Study 1, an exploratory factor analytic procedure (N = 292) resulted in a17-item measure with four underlying factors: (a) Perseverative Cognition, (b) Secondary Appraisal, (c) Anticipatory Race-Related Stress Scale–Psychological, and (d) Anticipatory Race-Related Stress Scale–Physiological. In Study 2 (N = 227), a confirmatory factor analytic procedure was conducted to evaluate and compare the underlying factor structure for several competing models of the PARS. This procedure supported a four-factor oblique solution as having the best fit to the data. Study 2 also provided evidence for the convergent validity of the PARS in that its factor scores correlated, in the anticipated direction, with scores on measures of related constructs.